In this article four species of Desmodoridae, Desmodora alberti sp. nov., Desmodora marci sp. nov., Desmodorella balteata sp. nov. and Desmodorella spineacaudata sp. nov. (Nematoda: Desmodoridae) are described from hydrothermal vents of the Pacific. The genus Desmodora is revised and lists of valid species are provided; four subgenera are reinstated as genera; Xenodesmodora is regarded as genus inquirendum. Definitions of some morphological structures are given.