Functionally defined clones and lines of murine lymphocytes including myelomas, helper, suppressor and cytolytic T lymphocytes were analyzed for their glycosphingolipids (GSLs). GSLs were characterized by thin-layer chromatography and by high-performance liquid chromatography. Lymphocytes with different functions displayed, besides a number of common GSLs, some characteristic GSLs that may be regarded as markers. Globotriaosylceramide was found on myelomas and B blasts, whereas globotetraosylceramide was confined to helper T cells. All T cells including cytolytic T lymphocytes displayed gangliotetraosylceramide (asialo-GM1) as a major GSL, which was further characterized by sequential degradation with exoglycosidases.