Background: Thyroid disorders are the most common endocrinopathies encountered during pregnancy in India. Thyroid gland and its functions are immensely influenced by pregnancy. This study was designed to evaluate the prevalence of subclinical hypothyroidism in pregnancy and its foeto-maternal outcome amongst the pregnant mothers having such disorder. Methods: In this hospital based, observational, comparative study, which was carried out on 200 pregnant women attending secondary care hospital of subhimalayan region for the duration of 1 year (2017 to 2018).Morning blood samples of study participants were analyzed for free T4, TSH in their first trimester, and they were followed up till the time of confinement for foeto-maternal outcome. Results: prevalence of thyroid disorder was 16% which was high as compare to other regions of India. Subclinical hypothyroidism was highly prevalent (13.5%) and masked, associated with adverse maternal outcomes like anaemia (p=0.001), abortion (p=0.012), postpartum haemorrhage (p=0.012), puerperal sepsis (p=0.008) and adverse foetal outcome like foetal growth restriction (p=0.034) as compared to euthyroidism. Conclusion: In a developing country like India where undiagnosed thyroid disorders especially subclinical hypothyroidism is highly prevalent and associated with adverse foeto-maternal outcomes, our study recommends universal screening of pregnant women for such disorders.