All stillborn and all deceased children were autopsied during a 27-year period in a given territory with some 1,220,000 inhabitants. Of the 3969 stillborn children, 81 (2.1%) had a congenital heart malformation. Out of the 470,188 liveborn children, 13,629 died before the age of 15 years. Autopsy demonstrated a heart malformation in 1008 (0.21%) of these liveborn children. Thus, with 1089 cases found in the combined stillborn and liveborn and later deceased children, congenital heart malformation was found in 6.2% of all autopsied children. This represented 7.4% of the total mortality of liveborn children and 41.4% of all congenital malformation discovered in the deceased children. In total, 2257 congenital heart lesions were identified with a mean of 2.1 lesions per child. The lesions were classified in 37 categories of heart malformation. The most common malformation was ventricular septal defect, followed by hypoplastic left ventricle and complete transposition. The most frequent heart lesion was also ventricular septal defect followed by patency of the arterial duct. The frequency of the different heart malformations in stillborns differed from that in the liveborn children. The ratio of boys and girls in the overall series was 1.28:1, with pronounced differences in sex distribution being observed in some malformations.