The embryonic/fetotoxic effects of DEHP on pregnant mice (ddY-Slc female x CBA male) were studied. DEHP was administered orally in dosages of 0.05 ml/kg to 30.0 mg/kg on day 6, 7, 8, 9 or 10 of gestation. A single administration of DEHP over 0.1 ml/kg (1/300 of LD50) on day 7 of gestation decreased the numbers and the body weight of living fetuses, whereas no significant changes in the numbers of living fetuses (with no gross and skeletal abnormalities) were observed compared with those of the control group, when 0.05 ml/kg (1/600 of LD50) of DEHP was administered. The fetotoxicity (fetal death) was dose dependent. The LD50 and the nonfetolethal maximum dosage of DEHP in its single, oral administration was 592 mg/kg and 64 mg/kg, respectively. The latter value is much higher than an estimated DEHP intake from commercial foodstuffs in men, which is approximately 0.03 mg/kg/day.