The water scavenger beetle genus Phaenostoma d'Orchymont, 1937 is reviewed and redescribed. Two new species are described: P. kontax sp. nov. (Peru) and P. stochasma sp. nov. (Costa Rica, Venezuela). The only previously known species, P. posticatum (Sharp, 1887) is newly recorded from Costa Rica and redescribed. A key to known species of the genus is presented.