A total of 43 species and 1 variety of mosses in 22 genera and 9 families were observed in the Ayer Hitam Forest Reserve, Selangor. This represents 9.1% of the 481 taxa of mosses reported for Peninsular Malaysia and Singapore. Seven species viz. Fissidens papillosus, Syrrhopodon fimbriatulus, Pyrrhobryum latifolium, Acroporium lamprophyllum, Papillidiopsis malayana, Radulina hamata and Trichosteleum mammosum are reported for the first time for the state of Selangor and Fissidens guangdongensis is a new record for Peninsular Malaysia. Calymperaceae is the largest family with 5 genera and 18 species, followed by Sematophyllaceae (8 genera, 10 species), Hypnaceae (3 genera, 5 species) and Fissidentaceae (1 genus, 5 species).