Filed Pursuant to Rule 497(e)

Registration No. 033-61254

GABELLI CAPITAL SERIES FUNDS, INC.

GABELLI CAPITAL ASSET FUND (the “Fund”)

Supplement dated February 7, 2013, to the Fund’s Statement of Additional Information, dated April 27, 2012

Effective immediately, the following changes apply to the Statement of Additional Information for the Fund.

The second, third and fourth paragraphs on page 9 under the sub-section “Hedging Transactions” are deleted. The following is added on page 11 before the sub-section “Asset Coverage for Forward Contracts, Options, Futures, and Options on Futures”:

“Limitations on the Purchase and Sale of Futures Contracts, Certain Options and Swaps. Subject to the guidelines of the Board, the Fund may engage in “commodity interest” transactions (generally, transactions in futures, certain options, certain currency transactions and certain types of swaps) only for bona fide hedging or other permissible transactions in accordance with the rules and regulations of the Commodity Futures Trading Commission (“CFTC”). Pursuant to amendments by the CFTC to Rule 4.5 under the Commodity Exchange Act (“CEA”), the Adviser has filed a notice of exemption from registration as a “commodity pool operator” with respect to the Fund. The Fund and the Adviser are therefore not subject to registration or regulation as a commodity pool operator under the CEA. Due to the recent amendments to Rule 4.5 under the CEA, certain trading restrictions are now applicable to the Fund as of January 1, 2013. These trading restrictions permit each Fund to engage in commodity interest transactions that include (i) “bona fide hedging” transactions, as that term is defined and interpreted by the CFTC and its staff, without regard to the percentage of the Fund’s assets committed to margin and options premiums and (ii) non-bona fide hedging transactions, provided that the Fund does not enter into such non-bona fide hedging transactions if, immediately thereafter, either (a) the sum of the amount of initial margin deposits on the Fund’s existing futures or swaps positions and option or swaption premiums would exceed 5% of the market value of the Fund’s liquidating value, after taking into account unrealized profits and unrealized losses on any such transactions, or (b) the aggregate net notional value of the Fund’s commodity interest transactions would exceed 100% of the market value of the Fund’s liquidating value, after taking into account unrealized profits and unrealized losses on any such transactions. Therefore, in order to claim the Rule 4.5 exemption, the Fund is limited in its ability to invest in commodity futures, options and certain types of swaps (including securities futures, broad-based stock index futures and financial futures contracts). As a result, in the future, the Fund will be more limited in its ability to use these instruments than in the past and these limitations may have a negative impact on the ability of the Adviser to manage the Fund, and on the Fund’s performance.”

Please retain this Supplement with your Statement of Additional Information for reference.