Teratogenic and embryotoxic effects of fipronil insecticide were studied following orally intubation of pregnant female rats. The animals were treated with different doses 1/10 LD 50 (2.1 mg/kg b.wt) and 1/30 LD 50 (0.7 mg/kg b.wt) at the 6 th to 15 th days of pregnancy (time of organogenesis). At the 20 th days of pregnancy, pregnant females were subjected to a caesarean section. The effect of the fipronil on fetal development was evaluated. Maternal weight gain decreased at 1/10 and 1/30 LD 50 of fipronil. The body weight and length of viable fetuses significantly decreased with both tested doses. Visceral examination revealed cleft palate, heart and lungs hypoplasia, liver and kidneys atrophy increased with fipronil treatments at different doses. Skeletal examination showed incomplete ossification of the skull bones, short ribs, coccygeal absences, sternbrae abscence and digits of fore and hind limbs.