Antibiotic therapy is the most common for treating the UTIs during gestation, Trimethoprim Sulfamethoxazole (TMP-SMX) is one of antifolate used in such therapies. Current study was done to test the ability of TMP-SMX to induce developmental defects in mice fetuses. Different concentrations of the drug, 0.00, 4.10, 8.33 and 16.66 µg/g B.W. were administered orally to the dams on days 6-12 of gestation, and fetuses were recovered on day 18. Morphological observations of fetuses from 4.10, 8.33 and 16.66 µg/g B.W. dose groups showed abnormalities such as skin hemorrhages, microphthalmia, limb deformities, hygromas, kyphosis, curved and short tail and fluid filled abdominal cysts. Significant increase in intrauterine growth retardation and resorptions of fetuses, with increasing dose concentration, was also observed. Morphometric observations of fetal body parts like head circumference, eye circumference, forelimb and hindlimb size and tail length demonstrated a significant (P<0.005) decrease with increasing dose concentrations in comparison with control group. The fetal body weight and CR length reduced significantly (P<0.005) in all dose group. Trimethoprim Sulfamethoxazole has significant potential to cause congenital defects in developing embryo.