The lipid composition of purified erythrocyte membrane glycophorin was measured. Diphosphoinositide, triphosphoinositide and phosphatidylserine are the major phospholipids in glycophorin preparations. Nearly all of the radioactive diphosphoinositide and triphosphoinositide extracted from erythrocyte membranes by lithium diiodosalicylate are recovered in purified glycophorin. There appeared to be no significant enrichment of other acidic membrane phospholipids in the protein. It is not clear if the polyphosphoinositides are associated specifically with the membrane protein or whether fortuitous binding has occurred during purification.