The progress in the experimental and epidemiological studies on the mutagenic and carcinogenic effects of gasoline engine exhausts were reviewed in the present paper. Current data showe that gasoline engine exhaust is a genotoxic agent and mutagen to bacteria, animal and human, but for its carcinogenic effects on animal by inhalation route, no new report has been published. So far no consistent relationship has been seen between cancer risk and gasoline engine exhaust exposure in epidemiological fields.