Objective: To determine the frequency thyroid dysfunction in patients with type 2 diabetes patients seen at Dow University Hospital, Karachi. Methodology: This observational study was carried out at National Institute of Diabetes & Endocrinology at Dow University Hospital, Ojha Campus, Karachi, Pakistan from January 2015 to December 2015. All type-II diabetes mellitus (DM) patients with more than 5 years duration were evaluated for thyroid status. All those who had proven thyroid disorder and on treatment, Type 1 DM, patients with gestational diabetes mellitus, fibrocalculous pancreatitis, pancreatitis and steroid induced diabetes were excluded. The laboratory evaluation of thyroid functions was done by estimation of serum T3, T4 and TSH levels. Results: Out of 288 patients, male to female ratio were 1:1.28 and mean age was 51.2+6.18 years (range 30 to 70 years). 119(41.31%) patients suffered DM for 5 to 10 years, 99(34.37%) patients for 5 years and 70(24.30%) had more than 10 years duration. Mean TSH level was 2.280 +/- 1.42 mU/L, mean free T4 was 8.24 +/- 13.12 mu mol/L and mean free T3 was 95.12 +/- 26.14 mu mol/L. Hyperthyroidism was observed in 38(13.19%) patients and sub-clinical hypothyroidism in 19(6.59%) patients while rest of 231(80.20%) cases were within normal range. Conclusion: Patients with DM should be screened for thyroid function as unrecognized thyroid dysfunction can lead to metabolic disturbances and also an increased risk of fatal atherosclerotic events. (Rawal Med J 201;42:5255)