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 (≥15years 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.