The effects of choice of solvent and period of extraction on recovery of phospholipid classes extracted from rat erythrocyte membranes were investigated. For extraction of phosphatidylserine (PS) the best recovery was achieved using chloroform-methanol (2:1, v/v), for diacyl phosphatidylethanolamine (PE) acetone-isopropanol (3:2, v/v), and for extraction of plasmalogen PE, phosphatidylcholine (PC) and sphingomyelin (SM) using hexane-isopropanol (3:2, v/v). Using hexane-isopropanol (3:2, v/v), boiling during the extraction increased the recovery of some of the individual phospholipid classes whereas mechanical treatment of the sample had only a slight effect. Furthermore, the fatty acid composition of PS and PE varied most with different extraction conditions and the phospholipid classes PC and SM were extracted more readily from rat erythrocyte membranes than PS, diacyl and plasmalogen PE.