Male rats were repeatedly given 1,2-dibromo-3-chloropropane (DBCP) at 10, 30, or 100 mg/kg twice a week for 12 weeks and were examined pathologically at the 12th, 24th and 36th week. DBCP produced primary lesions in kidneys and testes dose-dependently. The renal lesions were the lining of the proximal tubules in the outer medulla by enlarged, occasionally giant, epithelial cells. Testicular lesions were the atrophy of the seminiferous tubules. These lesions were qualitatively and quantitatively similar throughout the experiment. The results indicated that repeated exposure of relatively low doses of DBCP produced irreversible lesions in the kidney and testis, and that the effects on these tissues may be cumulative.