Endothelial dysfunction is the postulated link between coronary artery disease (CAD) and erectile dysfunction (ED). Brachial artery flow-mediated vasodilatation (FMD) is a non-invasive surrogate marker for endothelial function assessment. Despite Asian Indians representing a considerable global CAD burden, data on FMD and ED in these patients are lacking. Of the 225 patients undergoing coronary angiography, 72% had ED (assessed using the International Index of Erectile Function (IIEF-5) questionnaire); ED was moderate to severe in 61% of the patients. ED patients had a higher incidence of severe and diffuse angiographic CAD, a greater number of coronary vessels involved and a lower mean brachial artery FMD (6.40%±4.60% vs. 9.10%±4.87%, P<0.001) compared to non-ED patients. A progressive reduction in FMD was noted with increasing severity of ED. Impaired FMD (≤5.5%) was twice as common in ED patients (52% vs. 24% without ED). Patients with impaired FMD had higher ED prevalence (85% vs. 62%) and lower mean IIEF-5 scores compared to those with normal FMD. Impaired FMD was a significant ED predictor independent of other risk factors (odds ratio, 2.33; 95% confidence interval: 0.59-9.23; P=0.03). An inverse correlation between FMD and ED severity was observed (r=-0.22; P=0.004). ED is common among Asian Indians with angiographically documented CAD. Patients with ED have impaired FMD independent of other risk factors, suggesting that endothelial dysfunction is the underlying pathophysiology. Urologists and cardiologists need to be aware of the association between ED, CAD and endothelial dysfunction.