Alterations in lipid constituents of lamb liver in response to varying doses (O-2.0 Mrad) of gamma-radiation were ascertained in terms of total vitamin A, total phospholipid, and fatty acid content. Radiation exposure at 2.0 Mrad dose resulted in a five-fold increase in thiobarbituric acid reacting substances (TBRS) measured in terms of malonaldehyde and a 64% rise in carbonyls. The losses in lipid constituents were marginal. During the course of autolysis significant lipolytic activities persisted in irradiated lamb liver as evidenced by the decline in total phospholipid (50%) and neutral fat levels accompanied by a four-fold increase in fatty acid content. In irradiated lamb liver undergoing autolysis, a rapid hydrolysis of vitamin A Esters occurred leading to enhanced vitamin A alcohol/ester ratios. A comparison of radiation destruction of vitamin A in model systems, shark liver oil, and lamb liver revealed that similar doses of gamma-radiation cause more destruction in model systems than in others.