X0303 4 2011-01-31 false 0001284812 COHEN & STEERS INC CNS 0001181496 COHEN MARTIN 280 PARK AVENUE, 10TH FLOOR NEW YORK NY 10017 true true true false Co-Chairman, Co-ChiefExecutive Common Stock 1340701 I By the Martin Cohen 1998 Family Trust Common Stock 2011-01-31 4 A false 79266 0 A 10735610 D Shares held by the Martin Cohen 1998 Family Trust for the benefit of Mr. Cohen's family. Mr. Cohen's spouse is the trustee of the trust. Mr. Cohen disclaims beneficial ownership of these shares, and the filing of this report is not an admission that Mr. Cohen is the beneficial owner of these shares for the purposes of Section 16 and for any other purpose. Includes 63,413 restricted stock units (RSUs) mandatorily deferred by CNS from the reporting person?s annual incentive performance bonus, plus 15,853 RSUs granted to the reporting person as a company match on such deferral. Dividends paid on CNS common stock are reflected in additional RSUs on such deferred and matching RSUs. The deferred and matching RSUs vest ratably over four years, and the dividend RSUs vest on the fourth anniversary of the grant. Salvatore Rappa, Attorney-in-Fact 2011-02-01