The taxonomic position of Flavobacterium okeanokoites IFO 12536T (T = type strain) was determined by 16S rRNA gene sequencing and chemotaxonomic methods. Phylogenetic evidence derived from a 16S rRNA sequence analysis indicated that F. okeanokoites, which forms rod-shaped cells, belongs to the genus Planococcus, which forms spherical cells. A phylogenetically close relationship was supported by chemotaxonomic characteristics, such as the presence of menaquinone 7 and menaquinone 8 as major isoprenoid quinones, the presence of phosphatidylglycerol, bisphosphatydylglycerol, and phosphatidylethanolamine as cellular polar lipids, and the G + C content of the DNA (46.3 mol%). These data suggest that whether a cell is a rod or a coccus is not a generic criterion. Accordingly, we propose that F. okeanokoites should be transferred to the genus Planococcus and that the description of the genus Planococcus should be emended.