The study of sudden death is one of the most important responsibilities of Forensic Pathology. A full investigation is necessary in order to find out the cause of death. However, currently there is no uniform method of study common to the different Institutes of forensic medicine. In this article we review the clinico-pathological characteristics of the diseases that have been associated with sudden cardiac death in children and young adults. We also present basic guidelines on clinical and pathological data for post-mortem investigations. The potential interest of molecular autopsy in the near future is underlined. In addition, the involvement of forensic pathology in preventive medicine is also emphasised. Sometimes sudden death is the first manifestation of potentially inherited cardiovascular diseases. In these cases, autopsy is the only opportunity for cardiological evaluation and genetic screening of relatives, which is essential for prevention of new episodes of sudden death among family members.