Biochemical parameters in blood specimens obtained from semi-adult rabbits of both sexes fed crude oil contaminated diets were examined. The diets had crude oil inclusions of 0, 0.05, 0.10, 0.15 and 0.20%. Blood samples were obtained from the marginal ear vein of representatives in each treatment group and assayed for urea, creatinine, total bilirubin, conjugated bilirubin and cholesterol. There were significant differences (P < 0.05) in biochemical parameters between control and crude oil treated animals. The biochemical changes observed indicate that ingestion of crude oil fractions cause disturbances in kidney and hepatocytes.