The use of crude oil in the treatment of diseases is gaining popularity in several parts of Nigeria. The impact of handling and storage on the toxicity profile of the Nigeria Crude oil has not been determined. A few hepatic and renal parameters were used in this study to assess the toxicity of crude oil samples found in different parts of Nigeria.  Three different crude oil samples from Onitsha market, Lagos markets and NNPC refinery Port Harcourt were administered orally for 30 days at three dose levels (750, 1500 and 3000 mg/kg) while the control was given water (10 ml/kg). There was a rise in serum BUN of 1500 mg/kg and 3000 mg/kg for both NNPC (Groups C & D) and Lagos (Groups I & J) samples while for Onitsha, a significant rise was observed only in the 3000 mg/kg dose group (Group G). Similarly, a significant percentage rise in creatinine was observed in 1500 mg/kg and 3000 mg/kg doses for both NNPC (Groups C & D) and Lagos (Groups I & J) samples, while all doses of crude oil from Onitsha showed no significant increase. Furthermore, all doses of the three samples of crude oil showed a significant percentage increase in serum levels of AST, whereas only the 1500 mg/kg dose of crude oil from NNPC showed a significant percentage rise in the serum levels of ALT. The results of the histological studies for the liver and kidney tissues demonstrated more abnormality in NNPC and Lagos samples than in the Onitsha samples. Conclusively, crude oil from the NNPC refinery and Lagos market was more toxic than the samples from the Onitsha market. Factors likely to contribute to differences in toxicity profiles could be exposure, environmental conditions, and time.