The phospholipid composition and the antioxidative activity (AOA) of lipids from liver, heart and brain of F1(CBA X C57Bl) mice change significantly after intraperitoneal injection of adriamycin (7 mg/kg). All tissues studied are characterized by a drastic fall in the phosphatidylethanolamine (PEA) content and the AOA of lipids with a minimum on the 2nd-4th days and a subsequent return to normal values on the 10th-14th days. These results are consistent with the hypothesis on the intensification of adriamycin-induced lipid peroxidation and the predominant expenditure of readily oxidized phospholipids, including PEA.