Introduction: Thyroid diseases and diabetes mellitus are the two most common endocrine disorders encountered in clinical practice which have been shown to mutually influence each other and association between both the conditions has long been reported. The present study aimed to find the prevalence of thyroid dysfunction with type 2 diabetes mellitus. Aim: The aim of the present study was to evaluate the prevalence of thyroid dysfunction in type 2 diabetes in south Indian subjects. Materials and methods: A total of 100 subjects aged 20–70 years were selected from Gandhi Medical College,Secunderabad. Glucose was estimated by “GOD–PAP”, enzymatic photometric test methodology. Thyroid profile was analyzed by chemiluminiscence immunoassay. Results: There was high prevalence of thyroid disorders in patients with type 2 Diabetes mellitus. Most common was hypothyroidism (8%), which was further found to be more in the age group>50 years (5%) in patients with uncontrolled Diabetes Mellitus i.e,FBS 217.5± 57.4. Conclusion: Screening of thyroid dysfunction should be done in all diabetic patients especially in patients with poor diabetic control.