Recent years have witnessed a change in our perception of congenital coronary artery anomalies. From being regarded as simple coronary angiographic observations of little clinical significance, they have come to be seen as potential causes of sudden death in young people and of myocardial ischemia in adults. Diagnostic difficulties, a lack of knowledge about the mechanisms through which they produce myocardial ischemia, and their highly variable incidence have made congenital coronary artery anomalies of great interest to cardiologists. This article focuses on the group of coronary artery anomalies that is responsible for most clinical events: anomalies that have their origin in the contralateral sinus of Valsalva. Coronary artery anomalies are defined, their incidence is discussed, diagnostic criteria are given, and finally a treatment algorithm based on current knowledge is proposed.