Congenital anomalous anatomy and course of coronary arteries are common however atresia of LMS is extremely a rare condition. Fewer than 50 cases of congenital atresia of left main stem coronary artery have been reported in the literature. The ostium or trunk of the left coronary artery is atretic, and the left coronary artery and its branches are supplied by the right coronary artery via coronary collaterals in a retrograde direction. The pattern of presentation varies depending on the age and anatomy of the patient. According to the literature these cases present at a very early age with signs of heart failure whereas adults may present with angina or shortness of breath. Its clinical signs and symptoms often resemble anomalous origin of the left coronary artery from the pulmonary artery and endomyocardial fibrosis. In literature there are only five adult cases reported with congenital atresia of LMS and an interesting fact is that one out of those five cases was diagnosed on autopsy to have atresia of LMS. That patient was a female at age of 76 years who died of reasons other than heart symptoms. Therefore it may be inferred that the range of symptoms vary from being completely asymptomatic to overt heart failure.