Introduction: Retinopathy is one of major micro vascular complication in long standing diabetes, but diabetic keratopathy has potential to decompensate following stress. The central corneal thickness is a sensitive indicator of health of cornea and may influence outcome in cataract, refractory surgeries and may lead to fallacy in Intraocular pressure measurement. Present study was cross sectional observational study, undertaken to determine the correlation between central corneal thickness (CCT), and diabetes control and duration in hilly north Indian patient. Material and Methods: This is a cross-sectional study conducted in the department of ophthalmology of a tertiary care centre in Kumaon region. 400 subjects from age group 40 to 80 years were studied. An ultrasound pachymeter was used to measure CCT. The subjects were divided into two groups, 200 of them were non-diabetic subjects, and 200 were diabetic patients. The collected data was transformed into variables, coded and entered in Microsoft Excel. Data was analysed and statistically evaluated using SPSS-PC-17 version. Results: The average central corneal thickness in diabetic patients was 527.01__ampersandsignplusmn; 25.57 microns. The average central corneal thickness found in non-diabetic patients was 513.38 __ampersandsignplusmn; 27.01 microns. The statistically significant (p__ampersandsignlt;0.001) increase in central corneal thickness found in diabetic patients compared to non-diabetic patients.CCT tends to increase significantly (p value__ampersandsignlt;0.05) in uncontrolled diabetes (HbA1C level __ampersandsigngt; 7%) and longer duration of diabetes. Conclusion: Diabetic patients had an increased central corneal thickness when compared with non-diabetic patients. And this is more in patient with longer duration of uncontrolled diabetes.