ABSTRACT The relative abundance of benthic foraminifera in Deep Sea Drilling Project Hole 586A (2,207 m) on the Ontong-Java Plateau in the western equatorial Pacific Ocean has been analyzed. The investigated sequence represents the time interval between 1.9 and 5.0 Ma. The relative abundance patterns for various species, composition of faunal assemblages and their variation through time, as well as sedimentological data has been used to develop a model for the paleoceanographic and paleoenvironmental evolution of the Ontong-Java Plateau area. Correspondence analysis shows that there are three significantly different assemblages present. Alternation in dominance between the three assemblages can be linked to major changes in the paleoenvironment. The benthic foraminiferal fauna contains 262 taxa assigned to 83 genera, of which 179 taxa have been illustrated and discussed in the taxonomic section. One genus, Siphoeggerella , is new.