Male albino rats were given ethanol (3.76 g/kg body weight/day) to induce hyperlipidemia. The rats showed increased concentration of cholesterol and triglycerides in the serum and tissues. Inclusion of coconut protein and L-arginine into ethanol fed rats produced lower levels of total cholesterol, LDL+ VLDL cholesterol, triglycerides and atherogenic index in the serum. Concentration of tissue cholesterol and triglycerides was also lower in these groups. Administration of coconut protein and L-arginine in the ethanol fed rats caused decreased activity of HMG-CoA reductase in the liver and increased activity of lipoprotein lipase in the heart. The activities of malic enzyme and glucose-6-phosphate dehydrogenase were also lower in these groups. Feeding coconut protein and L-arginine in ethanol treated rats showed increased concentration of hepatic bile acids and fecal excretion of neutral sterols and bile acids. All these effects were comparable in rats fed coconut protein and those fed L-arginine. These observations indicate that the major factor responsible for the hypolipidemic effect of coconut protein is due to the high content of L-arginine.