Isoxaben (82558-50-7) was evaluated for one-generation reproductive toxicity. The test material was administered orally by gavage to 20 artificially- inseminated Dutch Belted rabbits at 0, 100, 320, or 1000 mg/kg/day on gestation days 6-18. Maternal toxicity was indicated by one death and one abortion at 1000 mg/kg/day. These effects were due to nutritional deprivation due to anorexia induced by administered isoxaben. In surviving animals, food consumption and body weight gain were not adversly affected by treatement. Prenatal reproduction parameters (proportions of live and dead fetuses and resorptions), sex ratios, fetal weights, and proportions of fetuses with developmental variations and abnormalities were similar to controls. The no-effect level for maternal toxicity was 320 mg/kg/day and the no-effect level for prenatal toxicity and teratogenicity was at least 1000 mg/kg/day.