An investigation of the lipids of Oochoristica agamae, an anoplocephalid cestode of the Agama lizard, was undertaken. Total lipids of the parasite accounted for 8.4% of the fresh weight; neutral lipids comprised 82.98% of the total, glycolipids, 5.01%, and phospholipids, 12.03%. The major lipid classes in O. agamae include triglycerides, cholesterol, phosphatidyl choline, and phosphatidyl ethanolamine. The 16- and 18-carbon fatty acids were predominant in the parasite. Hexadecenoic acid, usually found at low concentrations in the lipids of helminth parasites, was the most abundant of the 16-carbon fatty acids of O. agamae (notably in the neutral lipid fraction). Although octadecatrienoic acid occurred only in trace amounts in the intestinal contents of the host, significant amounts of this fatty acid were detected in the parasite. A lack of 20-carbon fatty acids was determined in the lipids of the host's intestinal contents and the neutral lipid fraction of the parasite. O. agamae is suspected to be capable of modifying fatty acids obtained from dietary sources by chain elongation.