Sudden cardiac death is a major contributor to mortality in industrialized nations; in fact, it is the cause of more deaths than acquired immune deficiency syndrome, lung and breast cancer, and stroke together. Frequently, the autopsy becomes the principal diagnostic tool because macroscopic and microscopic analyses reveal the underlying cause of death. However, a significant number of sudden cardiac deaths remain unexplained. These cases are referred to as "natural" or arrhythmogenic. In the young, in up to 50% of sudden cardiac death cases, sudden death is the first and only clinical manifestation of an inherited cardiac disease that had remained undetected by conventional clinical investigations. To improve diagnosis, genetic testing has recently been added to these clinical tools. During the last two decades, there has been considerable progress in the understanding about genetics of sudden cardiac death. With that new information, the probands and their family members can make an informed decision regarding their care and know whether and to what extent they are at risk of suffering from the disease. Thus, genetic technology and expertise have become essential for the diagnosis of some forms of inherited cardiac diseases and to provide a basis for subsequent prevention strategies. This review focuses on recent advances in the understanding of cardiopathies owing to genetic investigations.