Coronary angiographic characteristics of fifty patients with type 2 diabetes mellitus and coronary artery disease (CAD) were compared with fifty non diabetic patients with CAD. Type 2 diabetic patients undergoing clinically indicated elective coronary angiography were individually matched with fifty non diabetic coronary artery disease patients for age, sex and major risk factors. No significant difference was present between the mean age, presenting complains and other coronary risk factors between the two groups. Severity and extent of coronary artery involvement was assessed by a coronary artery score (CAS) using the segmental distribution method for coronary artery lesions and morphometric analysis of atherosclerotic lesion was done. Type 2 diabetic patients had a higher CAS (11.74+/-5.04 vs 8.72+/-4.87; P<0.001) as compared to the non-diabetic patients. Multivessel disease were more prevalent in both the groups (82% vs 68%; P>0.05) but diabetic patients had significantly higher number of triple vessel disease (58% vs. 38%; P<0.001). Normal coronary arteries and single vessel disease were more prevalent in non-diabetic patients (32% vs. 18%; P<0.05). As compared to non-diabetic group diabetic patients had a higher total number of diseased vessels (78.66% vs. 68%; P<0.01), a higher lesion per patient ratio (3.94+/-1.80 vs 3+/-1.67:P<0.001) and more proximal lesions (40.83% vs. 34.70%; P>.05) though not statistically significant. Morphometric analysis of coronary artery lesions revealed that diabetic patients had significantly higher number of multiple irregularity lesions (24.37% vs. 15.33%; P<0.01) and lesions were more obstructive (lesion involving 70-90% of coronary lumen: 70.53.% vs. 57.33%; P<0.05). Though there was no significant difference between the systolic left ventricular function between the two groups but significant higher regional wall motion abnormality was found more in diabetic patients (76%vs 62%; P<0.01). So type 2 diabetic patients had more severe and extensive atherosclerotic lesion in their coronary arteries than the matched non diabetic control on coronary angiography suggesting an independent effect of diabetic mellitus on atherosclerotic process specially in our population.