Within a prospective study of 56,109 total births, 457 youngsters have been found to have congenital heart disease. The overall incidence is 8.14/1000 total births, 8.0/1000 for the Negro and 8.3/1000 for the white. A specific lesion has been identified for each patient and lesion frequencies given for each class of patient, stillbirth, neonatal death, infant death, childhood death, and survivors. The percentage of autopsies was 93% in the stillbirths, 89% in the neonatal deaths, and 76% for those dying after 28 days of age. Of those classified as having definite congenital heart disease, 93% have been examined by a pediatric cardiologist. The average follow-up time for the 272 survivors is 3 years. Thirty-five per cent of patients with ventricular septal defect surviving more than 6 months had their lesion close spontaneously; one-half of the survivors with tetralogy of Fallot were "atypical," and essentially equal numbers of blacks and whites had all types of coarctation of the aorta in line with the study population, which is 47% black and 53% white.