A new species of Stegocephalidae, Parandania unicoxae sp. nov., is reported from hydrothermal vents in the Okinawa Trough. It is the fourth species described in the genus Parandania Stebbing, 1899. The new species is most similar to P. boecki (Stebbing, 1888), but can be readily distinguished from P. boecki by the unilobate coxae 6-7.