Thyroid diseases are common disorders affecting women of reproductive age group and hence constitute the commonest endocrine disorder in pregnancy also. According to ACOG, the prevalence of hypothyroidism in pregnancy is 2–5%. Women with hypothyroidism are at an increased risk for early pregnancy loss , low birth weight, placental abruption, low IQ babies etc. So early detection and treatment prevents such adverse outcomes. Aim And Objective: To study the fetomaternal outcome among pregnant women with hypothyroidism.Study Design: This is a retrospective study that includes pregnant women from the year june 2016 to may 2017, which consists of 103 patients with hypothyroid in the Department of Obstetrics and Gynaecology, Rajendra Institute of Medical Sciences,Ranchi Results:The study consists of 103 patients with hypothyroidism out of 5034 deliveries (2.01%), in which 20 ( 19.4%) had overt hypothyroidism and 83( 80.5%) had subclinical hypothyroidism out of total hypothyroid patients. Conclusion:The present study shows significant association between hypothyroidism and adverse fetomaternal outcomes. So routine maternal thyroid function testing, especially serum TSH should be done as soon as pregnancy is confirmed.