The genus Pomatocalpa (Orchidaceae) is revised. The genus is found from India through Malesia and the Cape York Peninsula of northeastern Australia to Fiji, north to northeastern Himalaya and Taiwan, with its center of diversity in Thailand and Peninsular Malaysia. Thirteen species are recognized, three of which have two subspecies. Two new combinations are proposed. A key to the species is given, and all taxa are described with notes on distribution and ecology. Distribution maps and illustrations are provided for all taxa. The overall distribution patterns suggest that the genus originated in a wet tropical area in the western part of Malesia or southern mainland Asia more than 15 million years ago, and that the present occurrences in Taiwan, the Lesser Sunda Islands and areas east of Lydekker's line are derived from later migrations. Partly on the basis of results of a nonparametric test for extinction, Pomatocalpa kunstleri subsp. linearipetalum and P. tonkinense are considered extinct in the wild.