We compare the data of three studies of hospitalized infants with cardiac disease performed between 1967 and 1987. The studies were from the New England Regional Infant Cardiac Program (1967-1974), the Brompton Hospital (1973-1982), and the Northern Great Plains Regional Cardiac Program (1982-1987). Considering differences in classification among the studies, the distribution of cardiac anomalies during the first year of life is similar among the three studies. Although about 30% of infants are admitted during the first week of life and nearly 40% between 3 and 6 months, the proportion of infants admitted between 6 and 12 months was larger (25%) in the latest than in the earliest study (10%). There were also differences in the distribution of the diagnoses at various ages, reflecting changes in the patterns of care during the three eras.