ABSTRACTIntroduction:Hypothyroidism is a common endocrine disorder occurring in pregnancy. Maternal and fetal complications are present in these patients. Timely identification and treatment help in the prevention of complications. The aim of this study was to find out the prevalence of hypothyroidism among pregnant women attending the Outpatient Department of Obstetrics in a tertiary care centre.Methods:A descriptive cross-sectional study was conducted in a tertiary care centre after taking ethical approval from the Institutional Review Committee (Reference number: 08/2021). Data from 1 January 2016 to 31 December 2020 were collected between 1 November 2021 to 31 November 2021. All pregnant women who had undergone thyroid level assessment in each trimester (first, second and third) and had delivered in the same centre were included in the study. However, pregnant women with comorbidities like hypertension, overt diabetes mellitus, hyperthyroidism, renal disease, cardiac disease, and neurological disorder were excluded. Convenience sampling method was used. Point estimate and 95% Confidence Interval were calculated.Results:Among 216 pregnant patients, the prevalence of hypothyroidism was 74 (34.25%) (27.9240.57, 95% Confidence Interval). Maternal complications were seen in 33 (44.59%). The commonest complication was oligohydramnios 10 (13.51%) followed by preterm delivery 8 (10.81%).Conclusions:The prevalence of hypothyroidism among pregnant women was found to be higher than other studies done in similar settings.