Present research work was planned to study teratological effects of sodium arsenate in developing Mus musculus (mammalian model). Due to deficiencies in literature regarding orally induced teratogenicity of arsenate in developing mammalian embryos, this study was designed. Additionally, garlic (Allium sativum) extract was used to check its protective potential against sodium arsenate induced teratogenicity. LD50 value calculated in pregnant females was 147.00 µg/g B.W. Exposure groups were divided into acute (single exposure group GD6, double exposure group GD6 & 12, multiple exposure group GD6, 9 &12) and sub-acute (continuous GD 6 to12, dose + antidote group GD6 to12). Each acute and sub-acute exposure groups were further divided into three concentrations of sodium arsenate i.e. 18.25 µg/g B.W., 35.50 µg/g B.W. and 75.00 µg/g B.W, based upon the 12.5%, 25% and 50% of calculated LD50 values. Along with acute and sub-acute groups control and vehicle control groups were also maintained. On GD18, the pregnant females were anesthetized and gravid uteri were dissected out. The fetuses were recovered, weighed, observed and were preserved for further studies. A trend of decrease in maternal body weight with increase in concentration and exposure of sodium arsenate was seen together with increased number of still fetuses as compared to control and vehicle control groups. Fetal body weight, CR length, head and eye circumference, limb size and tail length showed a gradual decrease when compared with respective control and vehicle control groups. A dose dependent increase in morphological abnormalities like microcephaly, exencephaly, microphthalmia, anophthalmia, omphalocoel, kyphosis, scoliosis, open eye, runt fetuses and kinky tail were mainly observed during the studies.Histologically, ii defects such as spina bifida, meningomyelocoel, hydrocephaly and enlarged ventricles were noticed. Besides this ventricular septal defects, lungs hypoplasia and ectopia cardis were found in increasing order from acute to sub-acute exposure groups. The 50% fetuses from dose groups 75.00 mg/kg B.W. and 40% from dose group 37.50 mg/kg B.W. displayed decreased ossification as compared with control and vehicle control groups. Fetuses recovered from a group which was given garlic extract along with sodium arsenate exhibited normal development of fetuses except few dead embryos. In this group, fetal body weight, head and eye circumference, limb size and tail length were recorded as normal as controls and vehicle controls. Histologically, dose group 75.00 mg/kg B.W. of sodium arsenate in conjunction with 125 mg/kg B.W. Garlic extract exhibited enlarged ventricles of brain, however, 18.25 and 37.50 mg/kg B.W. + 125 mg/kg B.W. of garlic was observed near to controls and vehicle controls. Based upon the current results, we deduced that sodium arsenate had the potential to induce teratogenic effects in mammals and garlic extract might be a helpful tool against sodium arsenate induced fetotoxicity. There must be some stringent parameters followed by the industries for disposal of arsenate, so that arsenate concentration in drinking water could be managed to avoid exposure to expectant mammals especially the humans.