The feeding ecology of two species of sesarmid mangrove crabs, Perisesarma eumolpe (de Man, 1895) and P. indiarum (Tweedie, 1940), in Mandai Kechil, Singapore was studied through field observations and laboratory experiments. The latter comprised a series of three separate experiments to investigate mangrove leaf species preferences, leaf age preferences, and feeding rates on leaves. Results indicate: 1) both P. eumolpe and P. indiarum are mainly sediment grazers, but also feed on mangrove leaves and roots and occasionally animal matter; 2) both crab species prefer Avicennia alba Blume leaves to other, locally common, mangrove species, i.e., A. officinalis L, A. rumphiana Hallier f, Rhizophora apiculata Blume, Bruguiera gymnorhiza (L.) Sav.); 3) there is no significant preference for leaves of differing ages in the two species; and 4) no difference in daily fresh leaf consumption exists between the two crab species, with P. eumolpe consuming 22 ± 1.97 and P. indiarum consuming 14 ± 1.06 mg dry weight/wet mass g crab/day.