Furan forms as a result of thermal treatment of food and induces harmful effects on organisms. In our work, lycopene, furan, and a combination of the two were given to diabetic male rats for 28 days. Hematological changes, total protein and cholesterol, triglyceride, and albumin levels, alanine aminotransferase, aspartate aminotransferase, lactate dehydrogenase, and alkaline phosphatase activities of the serum, malondialdehyde levels, glutathione peroxidase, catalase, glutathione-S-transferase, superoxide dismutase activities, DNA damage in liver tissues and hepatic histopathological alterations were compared to a control group. There were significant changes in the liver function tests, DNA damage, activities of antioxidant enzymes, and malondialdehyde levels between diabetic control and non-diabetic control groups, between diabetic control and diabetic lycopene groups, and also between diabetic furan and diabetic control groups. In diabetic lycopene and diabetic furan + lycopene treated groups we designated the preventive effects of lycopene against diabetes and furan, however, on the analysed parameters only. In spite of some pathological alterations designated in diabetic furan treated group's liver, fewer pathological alterations were observed in furan+lycopene treated groups at the end of week 4. Consequently, lycopene significantly reduced furan- and diabetes-induced toxicity in rat liver.