The present study investigated the dietary effect of conjugated linolenic acid (CLnA) on lipid profiles and lipid peroxidations in alloxan-induced diabetes mellitus in rats. Diabetic rats were fed with 20% sunflower oil (diabetic control), sunflower oil supplemented with 0.5% CLnA, sunflower oil supplemented with 0.15% α-tocopherol, and sunflower oil containing 0.25% CLnA + 0.15% α-tocopherol. The results demonstrated that 0.5% CLnA, 0.15% α-tocopherol, and 0.25% CLnA + 0.15% α-tocopherol each on supplementation significantly lowered total cholesterol and non-HDL-cholesterol in comparison with the diabetic control group. The TAG level was significantly lowered in both the 0.15% α-tocopherol and 0.25% CLnA + 0.15% α-tocopherol groups. LDL-lipid peroxidation and erythrocyte membrane lipid peroxidation were reduced significantly in each of the experimental groups vs. the control group. The CLnA + α-tocopherol diet induced a greater reduction in membrane lipid and liver lipid peroxidation than the α-tocopherol diet alone. In conclusion, dietary CLnA exerts antioxidant activity as evidenced by reduced lipid peroxidation in chemically induced diabetes mellitus. Copyright © 2006 by AOCS Press.