Abstract: The purpose of this study was to investigate the hepatotoxic and nephrotoxic effects of kerosene and petrol-contaminated diets on male and female wistar albino rats after 12 weeks of chronic exposure. The LD50 values of kerosene and petrol were obtained as 212 and 128 mL kg-1 b.wt. of rats, respectively. The animals exhibited changes in behavioural pattern such as respiratory distress, sedation, coma and death with symptom being more severe with petrol when compared to kerosene. Serum L-alanine amino transferase (L-ALT), L-aspartate amino transferase (L-AST) and alkaline phosphatase (ALP) levels, 12 weeks after feeding male and female wistar albino rats with contaminated diets increased significantly (p≤0.05). Feeding rats with diets contaminated with kerosene and petrol for 12 weeks resulted in remarkable decrease in Final Body Weights (FBW) and Percentage Weight Increase (PWI) of test animals compared to control. There was, however, a significant (p≤0.05) increase in the relative weights of liver and kidney of male rats fed kerosene-contaminated diets when compared to the control. Histological examination of the liver and kidney indicated that kerosene and petrol-contaminated diets induced significant degenerative changes in the structural integrity of both the hepatic and renal cells. The result obtained in this study suggest that long term ingestion of kerosene and petrol indicated stress on animals which could possibly cause adverse effect on the kidney and impaired liver function.