UNITED STATES
                       SECURITIES AND EXCHANGE COMMISSION
                             Washington, D.C. 20549


                                  SCHEDULE 13G

                    Under the Securities Exchange Act of 1934
                                (Amendment No.)*

                         THE GREENBRIER COMPANIES, INC.
                         ------------------------------
                                (Name of Issuer)

                         Common Stock, without par value
                         -------------------------------
                         (Title of Class of Securities)

                                    393657101
                                    ---------
                                 (CUSIP Number)

                                 August 16, 2006
                                 ---------------
                      (Date of Event which Requires Filing
                               of this Statement)



Check the appropriate box to designate the rule pursuant to which this Schedule
is filed:

        [ ]      Rule 13d-1(b)
        [X]      Rule 13d-1(c)
        [ ]      Rule 13d-1(d)



*The remainder of this cover page shall be filled out for a reporting person's
initial filing on this form with respect to the subject class of securities, and
for any subsequent amendment containing information which would alter the
disclosures provided in a prior cover page.

The information required on the remainder of this cover page shall not be deemed
to be "filed" for the purpose of Section 18 of the Securities Exchange Act of
1934 ("Act") or otherwise subject to the liabilities of that section of the Act
but shall be subject to all other provisions of the Act (however, see the
Notes).


                                  Page 1 of 10





-----------------------                                      -------------------
CUSIP No. 393657101                     13G                  Page 2 of 10 Pages
-----------------------                                      -------------------

---------- ---------------------------------------------------------------------
        1  NAME OF REPORTING PERSON
           I.R.S. IDENTIFICATION NO. OF ABOVE PERSON

           S.A.C. Capital Advisors, LLC
---------- ---------------------------------------------------------------------
        2  CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP*
                                                                  (a) [ ]

                                                                  (b) [X]
---------- ---------------------------------------------------------------------
        3  SEC USE ONLY
---------- ---------------------------------------------------------------------
        4  CITIZENSHIP OR PLACE OF ORGANIZATION

           Delaware
--------------------- ----- ----------------------------------------------------
                         5  SOLE VOTING POWER

                            0
NUMBER OF             ----- ----------------------------------------------------
SHARES                   6  SHARED VOTING POWER
BENEFICIALLY
OWNED                       705,000 (see Item 4)
BY                    ----- ----------------------------------------------------
EACH                     7  SOLE DISPOSITIVE POWER
REPORTING
PERSON                      0
WITH                  ----- ----------------------------------------------------
                         8  SHARED DISPOSITIVE POWER

                            705,000 (see Item 4)
---------- ---------------------------------------------------------------------
        9  AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON

           705,000 (see Item 4)
---------- ---------------------------------------------------------------------
       10  CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES

           [ ]
---------- ---------------------------------------------------------------------
       11  PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (9)

           4.4% (see Item 4)
---------- ---------------------------------------------------------------------
       12  TYPE OF REPORTING PERSON*

           00
---------- ---------------------------------------------------------------------
                       *SEE INSTRUCTION BEFORE FILLING OUT


                                  Page 2 of 10





-----------------------                                      -------------------
CUSIP No. 393657101                     13G                  Page 3 of 10 Pages
-----------------------                                      -------------------

---------- ---------------------------------------------------------------------
        1  NAME OF REPORTING PERSON
           I.R.S. IDENTIFICATION NO. OF ABOVE PERSON

           S.A.C. Capital Management, LLC
---------- ---------------------------------------------------------------------
        2  CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP*
                                                                  (a) [ ]

                                                                  (b) [X]
---------- ---------------------------------------------------------------------
        3  SEC USE ONLY
---------- ---------------------------------------------------------------------
        4  CITIZENSHIP OR PLACE OF ORGANIZATION

           Delaware
--------------------- ----- ----------------------------------------------------
                         5  SOLE VOTING POWER

                            0
NUMBER OF             ----- ----------------------------------------------------
SHARES                   6  SHARED VOTING POWER
BENEFICIALLY
OWNED                       705,000 (see Item 4)
BY                    ----- ----------------------------------------------------
EACH                     7  SOLE DISPOSITIVE POWER
REPORTING
PERSON                      0
WITH                  ----- ----------------------------------------------------
                         8  SHARED DISPOSITIVE POWER

                            705,000 (see Item 4)
---------- ---------------------------------------------------------------------
        9  AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON

           705,000 (see Item 4)
---------- ---------------------------------------------------------------------
       10  CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES

           [ ]
---------- ---------------------------------------------------------------------
       11  PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (9)

           4.4% (see Item 4)
---------- ---------------------------------------------------------------------
       12  TYPE OF REPORTING PERSON*

           00
---------- ---------------------------------------------------------------------
                       *SEE INSTRUCTION BEFORE FILLING OUT


                                  Page 3 of 10





-----------------------                                      -------------------
CUSIP No. 393657101                     13G                  Page 4 of 10 Pages
-----------------------                                      -------------------

---------- ---------------------------------------------------------------------
        1  NAME OF REPORTING PERSON
           I.R.S. IDENTIFICATION NO. OF ABOVE PERSON

           Sigma Capital Management, LLC
---------- ---------------------------------------------------------------------
        2  CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP*
                                                                  (a) [ ]

                                                                  (b) [X]
---------- ---------------------------------------------------------------------
        3  SEC USE ONLY
---------- ---------------------------------------------------------------------
        4  CITIZENSHIP OR PLACE OF ORGANIZATION

           Delaware
--------------------- ----- ----------------------------------------------------
                         5  SOLE VOTING POWER

                            0
NUMBER OF             ----- ----------------------------------------------------
SHARES                   6  SHARED VOTING POWER
BENEFICIALLY
OWNED                       100,000 (see Item 4)
BY                    ----- ----------------------------------------------------
EACH                     7  SOLE DISPOSITIVE POWER
REPORTING
PERSON                      0
WITH                  ----- ----------------------------------------------------
                         8  SHARED DISPOSITIVE POWER

                            100,000 (see Item 4)
---------- ---------------------------------------------------------------------
        9  AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON

           100,000 (see Item 4)
---------- ---------------------------------------------------------------------
       10  CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES

           [ ]
---------- ---------------------------------------------------------------------
       11  PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (9)

           0.6% (see Item 4)
---------- ---------------------------------------------------------------------
       12  TYPE OF REPORTING PERSON*

           00
---------- ---------------------------------------------------------------------
                       *SEE INSTRUCTION BEFORE FILLING OUT


                                  Page 4 of 10





-----------------------                                      -------------------
CUSIP No. 393657101                     13G                  Page 5 of 10 Pages
-----------------------                                      -------------------

---------- ---------------------------------------------------------------------
        1  NAME OF REPORTING PERSON
           I.R.S. IDENTIFICATION NO. OF ABOVE PERSON

           Steven A. Cohen
---------- ---------------------------------------------------------------------
        2  CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP*
                                                                  (a) [ ]

                                                                  (b) [X]
---------- ---------------------------------------------------------------------
        3  SEC USE ONLY
---------- ---------------------------------------------------------------------
        4  CITIZENSHIP OR PLACE OF ORGANIZATION

           United States
--------------------- ----- ----------------------------------------------------
                         5  SOLE VOTING POWER

                            0
NUMBER OF             ----- ----------------------------------------------------
SHARES                   6  SHARED VOTING POWER
BENEFICIALLY
OWNED                       805,000 (see Item 4)
BY                    ----- ----------------------------------------------------
EACH                     7  SOLE DISPOSITIVE POWER
REPORTING
PERSON                      0
WITH                  ----- ----------------------------------------------------
                         8  SHARED DISPOSITIVE POWER

                            805,000 (see Item 4)
---------- ---------------------------------------------------------------------
        9  AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON

           805,000 (see Item 4)
---------- ---------------------------------------------------------------------
       10  CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES

           [ ]
---------- ---------------------------------------------------------------------
       11  PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (9)

           5.1% (see Item 4)
---------- ---------------------------------------------------------------------
       12  TYPE OF REPORTING PERSON*

           IN
---------- ---------------------------------------------------------------------
                       *SEE INSTRUCTION BEFORE FILLING OUT


                                  Page 5 of 10





Item 1(a)           Name of Issuer:
                    --------------

                    The Greenbrier Companies, Inc.

Item 1(b)           Address of Issuer's Principal Executive Offices:
                    -----------------------------------------------

                    One Centerpointe Drive, Suite 200
                    Lake Oswego, OR 97035

Items 2(a)          Name of Person Filing:
                    ---------------------

                    This statement is filed by: (i) S.A.C. Capital Advisors,
                    LLC, ("SAC Capital Advisors") with respect to shares of
                    common stock, without par value ("Shares"), of the Issuer
                    beneficially owned by S.A.C. Capital Associates, LLC ("SAC
                    Capital Associates") and S.A.C. MultiQuant Fund, LLC ("SAC
                    MultiQuant"); (ii) S.A.C. Capital Management, LLC, ("SAC
                    Capital Management") with respect to Shares beneficially
                    owned by SAC Capital Associates and SAC MultiQuant; (iii)
                    Sigma Capital Management, LLC ("Sigma Management") with
                    respect to Shares beneficially owned by Sigma Capital
                    Associates, LLC ("Sigma Capital Associates") and (iv) Steven
                    A. Cohen with respect to Shares beneficially owned by SAC
                    Capital Advisors, SAC Capital Management, SAC Capital
                    Associates, SAC MultiQuant, Sigma Management and Sigma
                    Capital Associates.

Item 2(b)           Address of Principal Business Office:
                    ------------------------------------

                    The address of the principal business office of (i) SAC
                    Capital Advisors and Mr. Cohen is 72 Cummings Point Road,
                    Stamford, Connecticut 06902 and (ii) SAC Capital Management
                    and Sigma Management is 540 Madison Avenue, New York, New
                    York 10022.

Item 2(c)           Citizenship:
                    -----------

                    SAC Capital Advisors, SAC Capital Management and Sigma
                    Management are Delaware limited liability companies. Mr.
                    Cohen is a United States citizen.

Item 2(d)           Title of Class of Securities:
                    ----------------------------

                    Common Stock, without par value


                                  Page 6 of 10





Item 2(e)           CUSIP Number:
                    ------------

                    393657101

Item 3              Not Applicable

Item 4              Ownership:
                    ---------

                    The percentages used herein are calculated based upon the
                    Shares issued and outstanding as of June 21, 2006 as
                    reported on the Issuer's quarterly report on Form 10-Q filed
                    with the Securities and Exchange Commission by the Issuer
                    for the quarterly period ended May 31, 2006.

                    As of the close of business on August 16, 2006:

                    1. S.A.C. Capital Advisors, LLC
                    (a) Amount beneficially owned: 705,000
                    (b) Percent of class: 4.4%
                    (c)(i) Sole power to vote or direct the vote: -0-
                    (ii) Shared power to vote or direct the vote: 705,000
                    (iii) Sole power to dispose or direct the disposition: -0-
                    (iv) Shared power to dispose or direct the disposition:
                    705,000

                    2. S.A.C. Capital Management, LLC
                    (a) Amount beneficially owned: 705,000
                    (b) Percent of class: 4.4%
                    (c)(i) Sole power to vote or direct the vote: -0-
                    (ii) Shared power to vote or direct the vote: 705,000
                    (iii) Sole power to dispose or direct the disposition: -0-
                    (iv) Shared power to dispose or direct the disposition:
                    705,000

                    3. Sigma Capital Management, LLC
                    (a) Amount beneficially owned: 100,000
                    (b) Percent of class: 0.6%
                    (c)(i) Sole power to vote or direct the vote: -0-
                    (ii) Shared power to vote or direct the vote: 100,000
                    (iii) Sole power to dispose or direct the disposition: -0-
                    (iv) Shared power to dispose or direct the disposition:
                    100,000


                                  Page 7 of 10





                    4. Steven A. Cohen
                    (a) Amount beneficially owned: 805,000
                    (b) Percent of class: 5.1%
                    (c)(i) Sole power to vote or direct the vote: -0-
                    (ii) Shared power to vote or direct the vote: 805,000
                    (iii) Sole power to dispose or direct the disposition: -0-
                    (iv) Shared power to dispose or direct the disposition:
                    805,000

                    SAC Capital Advisors, SAC Capital Management, Sigma
                    Management and Mr. Cohen own directly no Shares. Pursuant to
                    investment agreements, each of SAC Capital Advisors and SAC
                    Capital Management share all investment and voting power
                    with respect to the securities held by SAC Capital
                    Associates and SAC MultiQuant. Pursuant to an investment
                    management agreement, Sigma Management maintains investment
                    and voting power with respect to the securities held by
                    Sigma Capital Associates. Mr. Cohen controls each of SAC
                    Capital Advisors, SAC Capital Management, and Sigma
                    Management. By reason of the provisions of Rule 13d-3 of the
                    Securities Exchange Act of 1934, as amended, each of (i) SAC
                    Capital Advisors, SAC Capital Management and Mr. Cohen may
                    be deemed to own beneficially 705,000 Shares (constituting
                    approximately 4.4% of the Shares outstanding) and (ii) Sigma
                    Management and Mr. Cohen may be deemed to own beneficially
                    100,000 shares (constituting approximately 0.6% of the
                    Shares outstanding). Each of SAC Capital Advisors, SAC
                    Capital Management, Sigma Management and Mr. Cohen disclaim
                    beneficial ownership of any of the securities covered by
                    this statement.


                                  Page 8 of 10





Item 5              Ownership of Five Percent or Less of a Class:
                    --------------------------------------------

                    If this statement is being filed to report the fact that as
                    of the date hereof the reporting person has ceased to be the
                    beneficial owner of more than five percent of the class of
                    securities, check the following. [ ]

Item 6              Ownership of More than Five Percent on Behalf of Another
                    --------------------------------------------------------
                    Person:
                    ------

                    Not Applicable

Item 7              Identification and Classification of the
                    ----------------------------------------
                    Subsidiary Which Acquired the Security Being
                    --------------------------------------------
                    Reported on By the Parent Holding Company:
                    -----------------------------------------

                    Not Applicable

Item 8              Identification and Classification of Members of the Group:

                    Not Applicable

Item 9              Notice of Dissolution of Group:
                    ------------------------------

                    Not Applicable

Item 10             Certification:
                    -------------

     By signing below the signatory certifies that, to the best of his knowledge
and belief, the securities referred to above were not acquired and are not held
for the purpose of or with the effect of changing or influencing the control of
the issuer of the securities and were not acquired and are not held in
connection with or as a participant in any transaction having that purpose or
effect.


                                  Page 9 of 10





                                    SIGNATURE
                                    ---------

     After reasonable inquiry and to the best of my knowledge and belief, I
certify that the information set forth in this statement is true, complete and
correct.

Dated:  August 17, 2006

S.A.C. CAPITAL ADVISORS, LLC


By: /s/ Peter Nussbaum
    ------------------------------------
Name:   Peter Nussbaum
Title:  Authorized Person


S.A.C. CAPITAL MANAGEMENT, LLC


By: /s/ Peter Nussbaum
    ------------------------------------
Name:   Peter Nussbaum
Title:  Authorized Person


SIGMA CAPITAL MANAGEMENT, LLC


By: /s/ Peter Nussbaum
    ------------------------------------
Name:   Peter Nussbaum
Title:  Authorized Person


STEVEN A. COHEN


By: /s/ Peter Nussbaum
    ------------------------------------
Name:   Peter Nussbaum
Title:  Authorized Person


                                 Page 10 of 10