Objectives: The aim of this study was to explore the possible anatomical risk factors of coronary heart disease (CHD) such as vascular geometry of the left coronary artery and its branches using coronary angiography. Patients and Methods: The trunk length (T) of the left coronary artery, the curve angle of the left anterior descending artery (LAD) and the bifurcation angle between the LAD and the circumflex artery (Cx) were measured in 77 patients (age range 20-83, mean 58.9±11.68). Results: The atherosclerotic plaque existence was investigated in LAD and Cx. The mean values of the T length, LAD curve angle and the LAD-Cx bifurcation angle were respectively 12.86 mm, 140.99° and 94.07°. In patients who have atherosclerotic plaques in LAD, the mean value of the T lengths was found 2.5 mm shorter than those of the patients whose LADs are intact (p=0.020). On the other hand a significant negative correlation between the LAD curve angle and the bifurcation angle was found (p<0.001). Conclusion: In view of our results it can be suggested that geometrical pattern of LAD and its branches may be a congenital risk factor in development of CHD in patients who have no other risk factors. © Medical Journal of Trakya University. Published by Ekin Medical Publishing. All rights reserved.