Arrhythmogenic right ventricular dysplasia is a relatively newly described clinical entity that is more and more frequently recognized. It may explain an increasing number of unexpected, sudden deaths in young adults that are or are not preceded by cardiac symptoms. A genetic transmission of the disease has been suggested by the study of familial cases. A location on chromosome 14 appears to be responsible for this disease. In some patients, a superimposed inflammatory process mixed with the pattern of arrhythmogenic right ventricular dysplasia may explain the progressive deterioration of left ventricular function. The systematic study of electrocardiograms demonstrates prolongation of the QRS complex and repolarization abnormalities in the right precordial leads due to a parietal block. Multiple therapeutic approaches are now available. The first line of therapy remains antiarrhythmic drugs,which are effective in most cases.Ablative techniques,implantable difibrillators,and heart transplantation have been used in the most severe examples of the disease.