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 of Gabelli Equity Series Funds, Inc. (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: 5/29/07 /s/ Bruce N. Alpert ---------------- -------------------------------------------- Bruce N. Alpert, Principal Executive Officer I, Agnes Mullady, Principal Financial Officer and Treasurer of Gabelli Equity Series Funds, Inc. (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: 5/29/07 /s/ Agnes Mullady ----------------- ----------------------------------------- Agnes Mullady, Principal Financial Officer and Treasurer