Arrhythmogenic right ventricular cardiomyopathy (ARVC), or dysplasia, is a genetic heart muscle disease whose diagnosis is often a challenge for the clinician. It is one of the commonest causes of sudden cardiac death in the young. The classic description of the disease describes the end stage of a process where the myocardium, mainly of the right ventricle, has been substituted by fibrofatty tissue. Thus the early stages of the disease with subtle symptomatology are often missed. Unfortunately the risk of a fatal outcome is no less severe. The genetic basis is under investigations. Disease causing mutations in important cell adhesion genes (plakoglobin, desmoplakin) provide the basis for improved diagnosis and understanding of the pathogenesis. Animal models support the pathogenic theory that alterations on the integrity of the adhesion junction is followed by a cellular death and progressive fibrofatty replacement, the substrate for ventricular arrhythmias. Due the growing complexity and numerous phenotypic variations reported, sometimes in the same family, international registries have been created. The present review aims to summarise the current concepts on ARVC emphasising the genetic studies, the diagnosis, new diagnostic techniques and prognosis.