As filed with the Securities and Exchange Commission on June 2, 2005

                                                      Registration No. 333-41674

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

                           ------------------------

                       POST-EFFECTIVE AMENDMENT NO. 1 TO
                                   FORM S-8

                            REGISTRATION STATEMENT
                                     UNDER
                          THE SECURITIES ACT OF 1933

                           ------------------------
 
                        Selective Insurance Group, Inc.
            (Exact name of registrant as specified in its charter)

           New Jersey                                            22-2168890
(State or other jurisdiction of                                (I.R.S. Employer
 incorporation or organization)                              Identification No.)

                                --------------

                               40 Wantage Avenue
                             Branchville, NJ 07890
                   (Address of Principal Executive Offices)

                        Selective Insurance Group Inc.
                        Stock Option Plan for Directors
                           (Full title of the plan)

                                --------------

                            Michael H. Lanza, Esq.
                   Senior Vice President and General Counsel
                        Selective Insurance Group, Inc.
                               40 Wantage Avenue
                             Branchville, NJ 07890
                    (Name and address of agent for service)

                                --------------

                                (973) 948-3000
         (Telephone number, including area code, of agent for service)

                                --------------
                                With a copy to:
                             Paul T. Schnell, Esq.
                   Skadden, Arps, Slate, Meagher & Flom LLP
                               Four Times Square
                            New York, NY 10036-6522
                                (212) 735-3000
                                --------------



                               EXPLANATORY NOTE

Selective Insurance Group, Inc. (the "Company") is filing this Post-Effective
Amendment No. 1 to Registration Statement on Form S-8 to deregister certain
securities previously registered by the Company pursuant to its Registration
Statement on Form S-8 filed with the Securities and Exchange Commission (the
"Commission") on July 18, 2000, File No. 333-41674 (the "2000 Form S-8"), with
respect to shares of the Company's common stock, par value $2.00 per share,
and the associated preferred share purchase rights (the "Common Stock"),
thereby registered for offer or sale pursuant to the Selective Insurance
Group, Inc. Stock Option Plan for Directors ("Directors Plan"). A total of
450,000 shares of Common Stock were initially registered for issuance, offer
or sale under the 2000 Form S-8.

On April 27, 2005, the stockholders of the Company approved the Selective
Insurance Group, Inc. 2005 Omnibus Stock Plan (the "2005 Omnibus Plan"), which
replaces the Directors Plan. No future awards will be made under the Directors
Plan. According to the terms of the 2005 Omnibus Plan, the shares of Common
Stock that were available for grant under the Directors Plan, but not actually
subject to outstanding awards or forfeited, cancelled, exchanged, surrendered,
or not distributed, as of April 27, 2005, are available for issuance under the
2005 Omnibus Plan. The total number of such shares was 331,000 (the "Carryover
Shares"). The Carryover Shares are hereby deregistered. The 2000 Form S-8
otherwise continues in effect as to the balance of the shares of Common Stock
remaining available for issuance, offer or sale pursuant thereto.

Contemporaneously with the filing of this Post-Effective Amendment No. 1 to
Registration Statement on Form S-8, the Company is filing a Registration
Statement on Form S-8 to register the shares of Common Stock now available for
issuance, offer or sale pursuant to the 2005 Omnibus Plan, including, but not
limited to, the Carryover Shares.

There may be shares of Common Stock registered in connection with the
Directors Plan that are represented by awards under the Directors Plan that,
after April 27, 2005, are forfeited, cancelled, exchanged, surrendered, not
distributed, or otherwise result in the return of shares to the Company. The
Company may, from time to time, file additional post-effective amendments to
the 2000 Form S-8, and additional Registration Statements on Form S-8,
carrying forward such shares for issuance, offer or sale in connection with
the 2005 Omnibus Plan.



                                  SIGNATURES

                  Pursuant to the requirements of the Securities Act of 1933,
the registrant certifies that it has reasonable grounds to believe that it
meets all of the requirements for filing on Form S-8 and has duly caused this
Post-Effective Amendment No. 1 to Registration Statement on Form S-8 to be
signed on its behalf by the undersigned, thereunto duly authorized, in the
City of Branchville, State of New Jersey, on this 2nd day of June, 2005.

                                            SELECTIVE INSURANCE GROUP, INC.


                                            By: /s/ Gregory E. Murphy
                                                --------------------------------
                                                Name:   Gregory E. Murphy
                                                Title:  Chairman, President and
                                                        Chief Executive Officer


                               POWER OF ATTORNEY

                  Each person whose signature appears below constitutes and
appoints Gregory E. Murphy, Michael H. Lanza and Michele N. Schumacher, and
each of them, with full power to act without the other, such person's true and
lawful attorneys-in-fact and agents, with full power of substitution and
resubstitution, for him and in his name, place and stead, in any and all
capacities, to sign this Post-Effective Amendment No. 1 to Form S-8
Registration Statement, and any and all amendments thereto and to file the
same, with exhibits and schedules thereto, and other documents in connection
therewith, with the Securities and Exchange Commission, granting unto said
attorneys-in-fact and agents, and each of them, full power and authority to do
and perform each and every act and thing necessary or desirable to be done in
and about the premises, as fully to all intents and purposes as he might or
could do in person, hereby ratifying and confirming all that said
attorneys-in-fact and agents, or any of them, or their or his substitute or
substitutes, may lawfully do or cause to be done by virtue hereof.

                  Pursuant to the requirements of the Securities Act of 1933,
this Post-Effective Amendment No. 1 to Registration Statement on Form S-8 has
been signed below by the following persons in the capacities and on the dates
indicated.





                                                                                    
Signature                                  Title                                          Date

/s/ Gregory E. Murphy                      Chairman, President and Chief Executive        June 2, 2005
------------------------------------       Officer (principal executive officer)
Gregory E. Murphy


/s/ Dale A. Thatcher                       Executive Vice President, Chief Financial      June 2, 2005
------------------------------------       Officer and Treasurer (principal accounting
Dale A. Thatcher                           and financial officer)


/s/ Paul D. Bauer                          Director                                       June 2, 2005
------------------------------------
Paul D. Bauer


/s/ A. David Brown                         Director                                       June 2, 2005
------------------------------------
A. David Brown


/s/ C. Edward Herder                       Director                                       June 2, 2005
------------------------------------
C. Edward Herder


/s/ William M. Kearns, Jr.                 Director                                       June 2, 2005
------------------------------------
William M. Kearns, Jr.


/s/ Joan M. Lamm-Tennant                   Director                                       June 2, 2005
------------------------------------
Joan M. Lamm-Tennant


/s/ S. Griffin McClellan III               Director                                       June 2, 2005
------------------------------------
S. Griffin McClellan III


/s/ Ronald L. O'Kelley                     Director                                       June 2, 2005
------------------------------------
Ronald L. O'Kelley


/s/ John F. Rockart                        Director                                       June 2, 2005
------------------------------------
John F. Rockart


/s/ William M. Rue                         Director                                       June 2, 2005
------------------------------------
William M. Rue


/s/ J. Brian Thebault                      Director                                       June 2, 2005
------------------------------------
J. Brian Thebault