Glycolipids were isolated from the adrenal glands of seven strains of guinea pig by DEAE-Sephadex and Iatrobeads column chromatographies. The average lipid-bound sialic acid content of the adrenal glands was estimated to be 96.0 +/- 30.4 nmol/g fresh tissue. The ganglioside fraction contained two major gangliosides which accounted for 82% of the total lipid-bound sialic acid. They were identified as N-acetylneuraminylgalactosylceramide (GM4) and N-acetylneuraminyllactosylceramide (GM3). The neutral glycolipid fraction contained one major and three minor glycolipids. The major glycolipid was identified as galactosylceramide, which accounted for 81% of the total glycolipid. The other three glycolipids were identified as Forssman glycolipid (7%), lactosylceramide (5%), and gangliotriaosylceramide (7%). In all strains examined, the glycolipid patterns were similar.