The effect of bonny-light crude oil was assessed in adult albino rats. The rats were administered with 200, 400, and 800mg/kg body weight of the crude oil orally for 7 days. Fluid intake was measured daily, initial and final animal body was recorded. The toxic effects on the kidneys were assessed and histological studies carried out. The results revealed that the kidney cells were damaged; crude oil caused a destruction of the renal reserve capacity. There was a significant increase (p ≤ 0.05) in creatinine in the high dose group (800mg/kg), and a significant decrease (p ≤ 0.05) in urea concentration. Histological examination indicates that crude oil induced severe pathologic changes in the forms of necrosis and oedema.