A revision of the genus Phyllagathis Blume is presented under a wider generic concept than used by earlier authors. This section of the revision will focus exclusively on the species in Borneo and Natuna Island. Eighteen species are endemic to Borneo, and only P. steenisii is endemic to Natuna Island, a small Indonesian island off the northern coast of Sarawak. One new species is described and several new combinations are established with the inclusion of pentamerous genera into Phyllagathis.