• We prospectively examined 1016 infants and children with congenital heart disease (CHD) to detect additional malformation patterns. They were divided into two major groups. In the first group (n=881), the CHD either occurred alone or was accompanied by a major extracardiac malformation (n=68, 7.7%). In the second group (n=135, 13.3%), the CHD was part of a malformation syndrome, embryopathy, association, or complex. In one fourth of the 56 chromosomal syndromes, the underlying cytogenetic anomaly differed from trisomy 21. Fourteen of the 30 children with non-chromosomal malformation syndromes had Noonan's syndrome. Thirteen of the 27 embryopathies were due to rubella infection, but alcohol embryopathy occurred nearly as often (n=10). In those children with malformation associations (n=16) seven showed cardiofacial association. Three of the five children with malformation complexes had Ivemark disease. In this study, underlying disorders were found in one of eight children with CHD, a considerably higher percentage than that reported in earlier studies.