Silicoflagellates were studied from sediment samples recovered by the Ocean Drilling Program (ODP) from the East Equatorial Pacific Ocean. ODP Holes 1219A was examined to develop a silicoflagellate biostratigraphy for this site and a better understanding of the paleoceanographic history of the region. Silicoflagellates are sparse in the Paleogene, where radiolarians predominate, but fairly abundant in the Neogene. More than twenty taxa are identified altogether. Especially interesting are diverse Naviculopsis, which shed light on the evolution and variability of the group.