The Cenozoic Ostracoda recovered from two guyots in the western Pacific Ocean are investigated. A high percentage of the taxa have been restricted to the individual guyots, thus supporting recent evidence that high levels of endemism documented on these bathymetrically isolated sites are real and do not simply reflect lack of knowledge in that region. Changes in the Ostracoda assemblages (diversity, abundance, dominance, endemism, faunal turnover) are detailed, together with an analysis of the evolution of the major groups recovered. Biostratigraphical interpretations are limited as a result of the high incidence of endemic taxa. Preliminary evidence is emerging from these Ostracoda, however, of regional "events" in the Ostracoda assemblages that can be traced on different guyots.