Although known to European botanists since 1876, the genus Ptychococcus (Arecaceae: Arecoideae: Ptychospermatinae) of New Guinea has remained one of the most poorly known genera of the Ptychospermatinae. The present study, based on examinations of plants in the field, in herbaria, and in cultivation, reduces the number of species to two and presents a historical overview of this misunderstood genus, along with a taxonomic revision, a key, descriptions and synonymies of the two species. A neotype is designated for Ptychococcus paradoxus.