BACKGROUND Prevalence of hypothyroidism in India is higher compared to UK and USA. It is also higher in cities of India located inland in comparison to those located in coastal areas. Aims-We aimed to study the prevalence of hypothyroidism in urban population of Dibrugarh town of Upper Assam. MATERIALS AND METHODS This was a cross-sectional, community-based epidemiological study conducted in four community clinics, in four different wards of Dibrugarh town. All male and female natives of Dibrugarh town, aged > 12 years of age were asked to volunteer in thyroid camps held on every 2nd and 4th Friday and Saturday of every month from 1st January 2015 to 31st December 2016. Participants were excluded if they were seriously ill, pregnant, had thyroid surgery or on any drugs containing heavy metals (Lithium, Amiodarone), steroids (oral or inhaled). TSH, T3 and T4 was done and analysed in all patients. RESULTS A total of 1467 patients were screened, of which 117 patients were excluded due to inadequate data. 1350 patients were included in our study. Their mean age was 42.7 (+1.3 SD) years. 780 (57.78%) patients had normal thyroid results. 213 (15.78%) patients had overt hypothyroidism and 298 (22.07%) patients had subclinical hypothyroidism. 41 (3.04%) had hyperthyroidism and 17 (1.26%) had subclinical hyperthyroidism. CONCLUSION The urban population of Dibrugarh town shows higher prevalence of clinical as well as subclinical hypothyroidism than Indian average and its results resemble the studies done in hilly areas like Jammu and Kashmir than other inland or coastal cities of India.