The potential of 1,3-dichloropropene (1,3-DCP) to induce dominant lethal mutations in the germ cells of male CD rats following inhalation exposure was investigated. Groups of 11-week-old males (30 animals/group) were exposed to 1,3-DCP vapors by inhalation at targeted concentrations of 0 (negative control), 10, 60, and 150 ppm for 10 weeks (6 hr/day, 7 days/week). An additional group of 30 males (designated the pairfed group) was kept on dietary restriction for 10 weeks. This group served as a control for any effects of decreased feed consumption and the associated body weight loss on the dominant lethal indices in the males exposed to 1,3-DCP. At the termination of the exposures, each male was cohoused with naive adult virgin CD females for two consecutive mating trials (1 week/trial, 2 females/male). Females were necropsied 13 days after the conclusion of each weekly mating trial and the number of corpora lutea, live implantations, and resorptions were determined. There were no statistically significant increases in either the pre- or postimplantation embryonic/fetal loss in females mated with 1,3-DCP-exposed males relative to controls at any weekly mating period. Based on these results, it can be concluded that 1,3-DCP is not mutagenic to the male germ cells of CD rats at exposure levels < or = 150 ppm, the highest concentration tested.