To determine the frequency of subclinical hypothyroidism in patients with proliferative diabetic retinopathy. Cross Sectional Study. This study was conducted in Dow University Hospital, Dow University of Health Sciences, Karachi from 1 [st] January 2012 to 31 [st] December 2012. One hundred and nineteen patients attending the medicalOPD Dow University of Health Sciences were included in study.119 patients were enrolled in study.47.1% were male and 52.9% were female patients mean age was 55.75 +/- 7.85 years, Mean HbA1 [c] value was 8.02 +/- 1.46%, Subclinical hypothyroidism was identified in 26.9% the patients. Subclinical hypothyroidism is associated with the development of proliferative diabetic retinopathy in the patients suffering from type 2 diabetics