Background: Coronary artery diameter is an important predictor of outcome after coronary interventions.There is very limited data available about coronary artery dimensions in an Indian population. Aim: To study the normal dimensions of the coronary artery segments in Indians without coronary artery disease by using quantitative coronary angiography.Material and method: 100 patients who have undergone coronary angiography with entirely normal coronary angiogram were included in our study.Results: This study showed the left main was larger in size followed by proximal LAD, proximal RCA & proximal LCX respectively (4.08 ± 0.44 mm, 3.27 ± 0.23 mm, 3.20 ± 0.37 mm, 2.97 ± 0.37 mm).When the vessel diameter was indexed to body surface area there was no statistical difference between males and females (p value > 0.05). Caucasians have larger coronary artery dimensions than Indians. But the vessel diameter indexed to body surface area showed no statistical significant difference between Indians and Caucasians (p value > 0.05).Conclusion: We found that coronary artery size indexed to body surface area is not statistically different between Indians and Caucasians. However with a smaller body habitus, Indians have smaller coronary arteries.