One-hundred and seven cases of congenital malformations of the heart were studied in a consecutive series of 2,876 autopsies. Ninety-two of these cases were observed in infants and children up to the age of 10 years. The sex ratio was 1.63 : 1 in favor of males. The congenital cardiac malformations were found to be more prevalent among Ashkenazi (11.8%) than among non-Ashkenazi (6.8%) children. No clear explanation for the different incidence of congenital malformation of heart among the 2 main ethnic groups of Jews could be given.