The free-living nematode, Caenorhabditis elegans, has been proposed and analyzed as a prototypic model for parasitic nematodes. In order to study whether there is a structural basis for the proposed analogy with respect to nematode glycoconjugates, we have analyzed Caenorhabditis elegans glycosphingolipids. Three, simple neutral glycosphingolipid components of the neutral glycolipid fraction were isolated by high-performance liquid chromatography. Structural analysis was performed by methylation analysis, exoglycosidase cleavage, matrix-assisted laser desorption/ ionization time-of-flight mass spectrometry, and ceramide analysis. The chemical structures have been determined as Glc beta 1Cer, Man beta 4Glc beta 1Cer and GlcNAc beta 3Man beta 4Glc beta 1Cer; that are characterized as belonging to the arthroseries of protostomial glycosphingolipids. The ceramide moiety of the parent glycosphingolipid-ceramide mono-hexoside was dominated by 2-hydroxy fatty acids, and a d17:1 spingoid-base with an iso- or anteiso-branched chain. The chemical composition of the three glycosphingolipids from Caenorhabditis elegans displayed close structural coincidence with the equivalent structures from the porcine parasitic nematode, Ascaris suum (G.Lochnit, R.D. Dennis, U.Zähringer, and R.Geyer, Glycoconjugate J., 1997), in support of this organism as a prototypic glycosphingolipid model for parasitic nematodes.