Lipid components of [Pseudomonas] echinoides NCIMB 9420 have been studied as an aid to taxonomic relocation of the organism. Non-polar lipids include the carotenoid nostoxanthin and the ubiquinone Q-10. The major fatty acids are cis-vaccenic acid [18:1(11c)], hexadecanoic acid (16:0) and 2-hydroxy-tetradecanoic acid (2-OH-14:0), but 11-methyloctadec-11-enoic acid[11-Me-18:1(11)] is a significant minor component. The preponderant phospholipids are phosphatidylethanolamine and phosphatidylglycerol; minor lipids include bis(phosphatidyl)glycerol and an unidentified aminophospholipid. Several glycolipids are present, the major one being a glucuronosylceramide derived from sphinganine with amide-bound 2-OH-14:0. The lipid profile supports a proposal to reclassify the organism as Sphingomonas echinoides.