The subchronic toxicity and carcinogenicity of 1,2-dichloropropane (DCP) in male and female B6D2F1 mice exposed to DCP by inhalation for 13 weeks or for 2 years was investigated. The DCP concentrations used were 50, 100, 200, 300 or 400 ppm (v/v) in the 13-week study, and 32, 80 or 200 ppm (v/v) in the 2-year study. Thirteen weeks inhalation exposure of mice to DCP caused death in the mice exposed to 300 ppm and above, and was found to induce hemolytic anemia and lesions of the liver, forestomach and heart. Two years exposure to DCP significantly increased the combined incidence of bronchiolo-alveolar adenomas and carcinomas in females and marginally increased the incidence of Harderian gland adenomas in males. As non-neoplastic lesion, atrophy and respiratory metaplasia in the olfactory epithelium, and respiratory metaplasia in the submucosal gland of the nasal cavity were increased. Thus, two years inhalation exposure to DCP is carcinogenic in female mice and there is a marginal evidence of carcinogenicity in males.