CERTIFICATION PURSUANT TO RULE 30A-2(B) UNDER THE 1940 ACT AND
                     SECTION 906 OF THE SARBANES-OXLEY ACT

I, Bruce N. Alpert, Principal Executive Officer & Principal Financial Officer of
The GAMCO Growth Fund (the "Registrant"), certify that:

         1.     The Form N-CSR of the Registrant  (the "Report")  fully complies
                with  the   requirements  of  Section  13(a)  or  15(d)  of  the
                Securities Exchange Act of 1934, as amended; and

         2.     The information  contained in the Report fairly presents, in all
                material  respects,  the  financial  condition  and  results  of
                operations of the Registrant.


Date:    March 10, 2006       /s/ Bruce N. Alpert
     --------------------     --------------------------------------------------
                              Bruce N. Alpert, Principal Executive Officer &
                              Principal Financial Officer