September 14, 1998
                                THE DREYFUS THIRD CENTURY
                                       FUND, INC.
                                SUPPLEMENT TO PROSPECTUS
                                  DATED OCTOBER 1, 1997
        THE FOLLOWING INFORMATION SUPPLEMENTS AND SUPERSEDES AND REPLACES ANY
CONTRARY INFORMATION CONTAINED IN THE TENTH PARAGRAPH IN THE SECTION OF THE
FUND'S PROSPECTUS ENTITLED "MANAGEMENT OF THE FUND."
        Paul A. Hilton serves as the Fund's primary portfolio manager with
respect to its areas of social concern. Mr. Hilton has been employed by The
Dreyfus Corporation since August 1998. From April 1997 through August 1998,
he was a Research Analyst in the Social Awareness Investment program at Smith
Barney Asset Management, a division of Travelers Group. From May 1995 through
April 1997, he served as a Project Director for corporate social
responsibility research at the Council on Economic Priorities.
        EFFECTIVE JANUARY 1, 1998, THE FOLLOWING INFORMATION SUPPLEMENTS AND
SUPERSEDES ANY CONTRARY INFORMATION CONTAINED IN THE PROSPECTUS UNDER THE
CAPTION "HOW TO BUY SHARES."
        The minimum initial investment is $750 for Dreyfus-sponsored Keogh
Plans, IRAs (including regular IRAs, spousal IRAs for a non-working spouse,
Roth IRAs, SEP-IRAs and rollover IRAs) and 403(b)(7) Plans with only one
participant and $500 for Dreyfus-sponsored Education IRAs, with no minimum on
subsequent purchases.
        EFFECTIVE JANUARY 15, 1998, THE FOLLOWING POLICIES WILL BE IN EFFECT
FOR THE FUND:
        ADDITIONAL INFORMATION ABOUT PURCHASES, EXCHANGES AND REDEMPTIONS.
The Fund is intended to be a long-term investment vehicle and is not designed
to provide investors with a means of speculation on short-term market
movements. A pattern of frequent purchases and exchanges can be disruptive to
efficient portfolio management and, consequently, can be detrimental to the
Fund's performance and its shareholders. Accordingly, if the Fund's
management determines that an investor is engaged in excessive trading, the
Fund, with or without prior notice, may temporarily or permanently terminate
the availability of Fund exchanges, or reject in whole or part any purchase
or exchange request, with respect to such investor's account. Such investors
also may be barred from purchasing other funds in the Dreyfus Family of
Funds. Generally, an investor who makes more than four exchanges out of the
Fund during any calendar year (for calendar year 1998, beginning on January
15th) or who makes exchanges that appear to coincide with an active
market-timing strategy may be deemed to be engaged in excessive trading.
Accounts under common ownership or control will be considered as one account
for purposes of determining a pattern of excessive trading. In addition, the
Fund may refuse or restrict purchase or exchange requests by any person or
group if, in the judgment of the Fund's management, the Fund would be unable
to invest the money effectively in accordance with its investment objective
and policies or could otherwise be adversely affected or if the Fund receives
or anticipates receiving simultaneous orders that may significantly
                              (CONTINUED ON REVERSE SIDE)
affect the Fund (E.G., amounts equal to 1% or more of the Fund's
total assets). If an exchange request is refused, the Fund will take no other
action with respect to the shares until it receives further instructions from
the investor. The Fund may delay forwarding redemption proceeds for up to
seven days if the investor redeeming shares is engaged in excessive trading
or if the amount of the redemption request otherwise would be disruptive to
efficient portfolio management or would adversely affect the Fund. The Fund's
policy on excessive trading applies to investors who invest in the Fund
directly or through financial intermediaries, but does not apply to the
Dreyfus Auto-Exchange Privilege, to any automatic investment or withdrawal
privilege described herein, or to participants in employer-sponsored
retirement plans.
        During times of drastic economic or market conditions, the Fund may
suspend the Exchange Privilege temporarily without notice and treat exchange
requests based on their separate components _ redemption orders with a
simultaneous request to purchase the other fund's shares. In such a case, the
redemption request would be processed at the Fund's next determined net asset
value but the purchase order would be effective only at the net asset value
next determined after the fund being purchased receives the proceeds of the
redemption, which may result in the purchase being delayed.
                                                                      035s0998