Chorocaris paulexa, new species, the first member of the genus Chorocaris Martin & Hessler, 1990 reported from the eastern Pacific, is described based primarily on two specimens, one of which is ovigerous, collected by the DSV Alvin at the Homer hydrothermal (black smoker) vent site (17°S) on the southern East Pacific Rise (SEPR). Seven additional (non-type) specimens from other SEPR sites (Rapa Nui, Brandon vents) are also described and compared to the types. The new species is compared to its congeners C. vandoverae Martin & Hessler, 1990, from the Mariana Back-Arc Basin in the western Pacific, and C. chacei (Williams & Rona, 1986), from the Mid-Atlantic Ridge), as well as to Mirocaris fortunata (Martin & Christiansen, 1995) (Mid-Atlantic Ridge). The new species is markedly similar in morphology to both Chorocaris vandoverae and C. chacei, but it can be distinguished from either of those species by a combination of the relatively acute branchiostegal projection of the carapace border, extent of the rostrum, and shape of the antennal scale. The finding extends the known range of the genus Chorocaris ~11,000 km eastward (from the Mariana Back-Arc Basin) and stimulates evolutionary and biogeographic hypotheses to explain this Pacific-wide distribution of a shrimp genus specialized to inhabit hydrothermal vent systems.