Introduction: Diabetes mellitus (DM) is one of the important health problems affecting the major populations worldwide. Diabetes mellitus, endocrine disorder which involves multiple organ systems and leads to significant morbidity and mortality due to accompanying complications. Thyroid diseases and diabetes mellitus are common endocrine disorders. The present study is carried out for the assessment of thyroid dysfunction in type 2 diabetic patients by measurement of serum T3, serum T4 and serum TSH levels. Materials & method: This study was conducted in Department of Biochemistry in association with Department of Medicine, Index Institute for Medical Sciences & Research Center, Indore. A total of 300 subjected were enrolled into the study. They were divided into 2 groups, 150 age and sex matched healthy subjects were taken as group I (controls) (HbA1c: 5.5 to 6.5 %) and 150 type 2 diabetes mellitus subjects were taken as group II (HbA1c: >7.5 %). Age of the study subjects was 30 to 70 years. Under aseptic conditions, 5 mL Fasting venous blood sample is collected from all subjects in vacutainers, Serum sample was used for the estimation of Fasting sugar (GOD-POD method) by using ERBA EM360 fully analyzer, thyroid profile by ELISA method, and EDTA sample is used for estimation of HbA1c by using Resin Binding Method. Data were expressed as mean ±SD. P value Results: fasting blood sugar and HbA1c levels were significantly increased in T2DM (group II) subjects compared with controls (group I). T3 levels were significantly decreased and TSH levels were significantly increased in T2DM subjects compared to controls. HbA1c is positively correlated with TSH Conclusion: In this present study, we have observed that the abnormal thyroid hormone levels among type 2 diabetics. Therefore, there is a need for the routine assay of thyroid hormones in type 2 diabetes mellitus in order to improve the quality of life and reduce the morbidity.