Diabetes mellitus and thyroid diseases are the two most common endocrinopathies encountered in clinical practice. Thyroid hormone abnormalities are frequently associated with diabetes and remain unidentified. Thyroid dysfunction could negatively impact Diabetes and its complications. Thyroid hormone replacement is associated with a decrease in Glycated Hemoglobin (HbA1c) level. The present study was undertaken to study association between thyroid profile and glycated Haemoglobin (HbA1c) in Type 2 Diabetes Mellitus patients. A case control study was done at Shri Krishna Hospital in Karamsad city .100 cases of Type 2 Diabetes mellitus and 100 healthy controls were taken. Blood samples were collected and analyzed for thyroid profile, HbA1c, Fasting Blood Sugar and Renal Function Test. We found that there was a positive correlation between TSH (Thyroid stimulating hormone) and HbA1c levels, and a negative correlation between Thyroid hormones [Triiodothyronine (T3) & Thyroxine (T4)] and Glycated Haemoglobin (HbA1c) in cases of type 2 Diabetes Mellitus. There is a significant decrease in TT3 (Total Triiodothyronine) and TT4 (Total Thyroxine) and significantly increased TSH in cases of Diabetes mellitus as compare to healthy Controls. We found that out of 100 cases of type 2 Diabetes Mellitus, 31% patients showed thyroid disorders. There is a high prevalence of thyroid disorders in Diabetic patients. If not diagnosed early, it could negatively affect diabetes and its complications. Therefore, routine screening of thyroid profile in diabetic patients is advisable to improve quality of life and reduce morbidity rate.