This study aims to examine the lung toxicity induced by benzo(a)pyrene (BaP), and to evaluate the ameliorative effect of wheat germ oil in respect to this toxicity. Mice were assigned into four groups (10 animals per group) as follows: G1, normal control group; G2, wheat germ oil (1.5 ml/kg body weight) control group; G3, BaP group that received an oral dose of BaP (40 mg/kg body weight) twice a week by a gastric tube; G4, which was treated by BaP as G3 group and then received a daily oral dose of wheat germ oil. All animals were sacrificed after four weeks. Administration of BaP was found to induce lung toxicity, represented by obvious increase of malondialdehyde (MDA), DNA fragmentation and decreased glutathione peroxidase (GPx) activity.  In addition, proliferation of alveolar cells, marked changes of type I and type II pneumocyte, deposition of collagen and thickening of interalveolar septum were seen in BaP-treated group. Treatment of the BaP group with wheat germ oil resulted in increase of GPx activity, decrease of MDA level, improvement of DNA fragmentation, amelioration of histopathology, and marked improvement of type I and Type II pneumocytes. It was concluded that administration of BaP can induce lung toxicity, but wheat germ oil has a ameliorative effect against this toxicity, probably due to its antioxidant effect.