Groups of 28 male and 28 female CD-1 mice and Fischer 344 rats were exposed to a mixture of 1,3-Dichloropropene and 1,2-Dichloropropane (D-D) vapors. Exposure concentrations were 0, 5 (4.7), 15 (14.4), or 50 (53.7) ppm, 6 h/d, 5 d/wk for 6 or 12 wk. The following parameters were evaluated: pharmacotoxic signs, body weights, hematology (HGB, HCT, RBC, WBC, and diff. leukocyte count), serum chemistry (BUN, GLU, ALB, GPT, and ALP), urinalysis, gross pathology, histopathology, organ weights, and organ weight/body weight ratios of brain, heart, liver, kidneys, testes or ovaries, and adrenals. The only exposure-related clinical effects observed were increased mean liver/body weight ratios of male rats and mean kidney/body weight ratios of female rats at the 50 ppm exposure level. Slight to moderate diffuse hepatocytic enlargement in 12 of 21 of the 50-ppm male mice after 12 wk exposure was the only compound-related histopathologic change present.