Procarbazine Hydrochloride (50 mg/kg, i.p.) causes micronuclei in hematopoietic cells, but does not increase the lacZ mutant frequency (MF) in bone marrow of mice, similar to that in liver, testis, spleen, kidney, and lung. Procarbazine Hydrochloride (50 mg/kg, i.p.) has positive effect on lung, bone marrow, and spleen for carcinogenesis. Procarbazine (450 mg/kg) significantly decreases testicular and epididymal weight and drastically reduces haploid cells and spermatogenic arrest in hamster.