Background: Thyroid dysfunction has been considered as one of the most common endocrine disorder in clinical practice throughout the world. Its increasing prevalence had led to the screening of general population in different parts of the world in order to investigate causes for rising incidence. A nationwide survey on epidemiology of thyroid dysfunction in selected cities of India suggested the need for further studies in order to have a more comprehensive analysis of epidemiological aspect for better awareness and control of this endocrine disorder. Aim: The major objective of the present study was to identify the prevalence and early age at onset of hypo and hyperthyroidism in post-iodization era based on a hospital based study. Materials and Methods: A total of 516 subjects visiting department of Medicine, Princess ESRA Hospital, Hyderabad, in age group of 10 to 75 years were included in the study from June 2013 to January 2014. Serum TSH, T3, and T4 assays were assessed by chemiluminescence method. Based on thyroid dysfunction test results, subjects were classified into Hypothyroidism, Subclinical Hypothyroidism and Hyperthyroidism. Results: The prevalence of hypothyroidism was highest in the females 33.52 % (n=173) as compared to males 2.32% (n=12) and hyperthyroidism in females 4.06% (n=21) and 0.19% (n=1) in males. Subclinical hypothyroidism in females was 7.55% (n=39). Conclusions: An inordinately high increase in the prevalence rate in women was observed particularly in the age group 21- 30years. Monitoring of thyroid profile is necessary to prevent adverse outcome at clinical and subclinical levels related to infertility, pregnancies and other complications.