Trimethylpropane trimethacrylate (CAS No. 3290-92-4) was evaluated for developmental toxicity. The test material was administered via gavage to 22 CD pregnant rats per group on days 6-15 of gestation at doses of 0 or 2500 mg/kg/day. Significantly lower survival rates and mean body weights were reported for treated dams. An increased incidence of clinical observations included wheezing, dyspnea, urine stains, rough haircoat, hunched posture, bloody crust on the eyes, nose, mouth, and front paws, salivation and alopecia. Lower uterine weights were also observed. An increased number of resorptions and mean incidence of resorptions,and a decreased mean incidence of live fetuses were reported. Significantly decreased fetal body weights (both sexes) and mean fetal length (females) were observed. No skeletal examinations were performed.