Background: The thyroid dysfunction particularly, subclinical hypothyroidism (SCH) is quite a common clinical condition in paediatric population but there is limited data available regarding its prevalence in children and adolescents in our population. The present study was aimed to know the prevalence of thyroid dysfunction particularly SCH in children and adolescents of northern Andhra Pradesh population and its association with hyperlipidemia.Methods: A retrospective study of 600 subjects (Children=272, Adolescents=328) between 6-19 years of age were included and the following parameters were examined: age, sex, total triiodothyronine (tT3), total tetraiodothyronine (tT4), thyroid stimulating hormone (TSH), total cholesterol, triglycerides (TGL), LDL and HDL cholesterol. The subjects were divided into group I and group II on the basis of age (in years), subjects between 6- ≤12 years age were grouped as group I and 12-≤19 years were as group II.Results: Out of 272 children and 328 adolescents studied, the prevalence of thyroid dysfunction was found to be 9.9% and 10.4 % respectively. The prevalence of subclinical hypothyroidism in children was 7.7% where as 4.9% in adolescents. In both the groups, females were predominantly affected with thyroid dysfunction as compared to males. Significantly elevated serum levels of total cholesterol, TSH and TGL were observed in SCH subjects when compared to euthyroid subjects (p<0.05). Statistically significant lower levels of HDL cholesterol were found in SCH as compared to euthyroids (p<0.05). However, no difference was noticed in the levels of total T3, total T4 and LDL cholesterol between SCH and euthyroids.Conclusions: The prevalence of thyroid dysfunction was found to be 10.2% in study population. SCH was observed in 7.7 % and 4.9% respectively in children and adolescent groups. Subclinical hypothyroidism (SCH) was the most predominant thyroid dysfunction found in our studied population with a prevalence of 6.2% (both children and adolescents). Correction of thyroid dysfunction particularly SCH in early childhood is highly essential to prevent the impairment of psychomotor and cognitive development.