A comprehensive taxonomic revision of the Philippine representatives of the genus Cyathocalyx (Annonaceae) is presented for the first time. Five species are recognized, including two endemics that are newly described (C. crassipetalus and C. samarensis). The utility of specific taxonomic characters is also evaluated, with particular emphasis on leaf indument and occurrence of crystals; sepal and petal shape; carpel number; monocarp size and shape; pericarp thickness; presence of stipes; seed size and shape; and prominence of the raphe. The conservation status of each species is evaluated according to current IUCN Red List categories and criteria.