Among 160 480 children born alive between 1960 and 1969 in Liverpool, 884 patients with structural congenital heart disease were identified. Data on these patients have been reviewed in order to estimate the number likely to need cardiac surgery during childhood and adolescence. Though only 33.9% of patients had surgery, we estimate that if current policies for management were followed, 475 (53.7%) patients would not require surgery. Extrapolation of this data suggests that each year in England and Wales approximately 830 infants (1383 per million livebirths) will require cardiac surgery within the first year of life and a further 1424 operations (2374 per million livebirths) will be required in later childhood or adolescence. No attempt has been made to estimate the number of operations for congenital heart disease which may prove necessary in adult life.