Introduction: Thyroid hormone abnormalities are commonest endocrine disorders in India and also the commonest preventable cause of mental retardation. Objectives-To determine the prevalence, clinical profile and etiology of thyroid dysfunction in children. Materials and Methods: A hospital based prospective observational study performed in newborns and children below 18 years fulfilling the inclusion criteria visiting the pediatric OPD and IPD in Ananta Institute of Medical Science & Research Centre Rajsamand, Rajasthan. If they had clinical suspicion of thyroid dysfunction. Patients having normal TSH levels defined by age wise cut offs were not evaluated further. Thyroid profile consisting of Free T4 , Total T4,TSH levels were done if there was suspicion of hypothyroidism and Free T3 and TSH if there was suspicion of hyperthyroidism. Other investigations like USG thyroid, thyroid 99m technetium scan anti TPO and anti TG antibody levels were done to look for the etiological diagnosis. Appropriate treatment was started according to standard guidelines. Results: Out of 252, 35 children were found to have thyroid dysfunction, 34 were having hypothyroidism and 01 was having hyperthyroidism. Overall male to female ratio in our study was 1:4. Most common clinical presentation in hypothyroidism cases were constipation followed by short stature. Autoimmune hypothyroidism was the most common etiology. Prevalence of goiter in the study was 20%. 07 cases were congenital hypothyroidism. Treatment was started according to standard guidelines. Conclusion: Autoimmune thyroid diseases are now the major leading cause of thyroid disorders in childhood. There is high prevalence of thyroid dysfunction in children in and around the rajsamand.