Isolated proximal anomalous connections of the coronary arteries (ANOCOR) are rare congenital abnormalities associated with a wide spectrum of clinical presentations and anatomic patterns ( Fig. 1 ). The prognosis of the ANOCOR depends mainly on the initial course of the ectopic vessel. But our knowledge of pathophysiology and natural history remains poor. Large-scale prospective multicenter registries dedicated to ANOCOR are needed to achieve a better understanding of these congenital coronary abnormalities. The ongoing ANOCOR study began in January 2010 with an inclusion period of 3 years. More than 450 young people (≥ 15 years old) and adults have been included by interventional cardiologists from the Interventional Working Group (GACI) of the French Society of Cardiology. A 5-year follow-up was scheduled. The design of the ANOCOR study will be presented.