Consanguineous marriages (Father’s sister’s daughter or mother’s brother’s daughter) are predominant in Southern states. An attempt is to study the prevalence of consanguineous marriages and its possible deleterious effect on pregnancy outcome in selected community in Tamil Nadu by collecting data from a household survey in Chidambaram Tehsil, covering 8 sample villages with 2665 households. Results revealed that the prevalence of consanguineous marriages found to be 26.79 percent and 7.6 percent women experienced spontaneous abortions. There is no significant association between marital relationship and place of residence with respect to spontaneous abortions however stillbirths found to be significantly higher among women with consanguineous marriages( χ² =2.5076, P<.001, RR: 1.45). 5.3 percent disability was observed among consanguineous marriages against 2.6 in non-consanguineous marriages (χ² =11.8752, P<.001, RR: 1.39). The proportion of child loss found to be more among consanguineous marriages and survived children around 8 percent had mental retardation, and 22.7 children became handicapped.