In a population based study including 35,218 infants born alive during the 15-year period 1982-1996, 360 (1%) were diagnosed having a congenital heart defect (CHD). At a follow-up 3-18 years later (median 9.5 years) 154 patients (42.8%) were spontaneously cured, of whom 142 (92.2%) had ventricular septal defects (VSD). 42 patients (11.7%) had died, 22 of whom (52.4%) during the neonatal period (0-28 days after birth). A total of 119 patients (33.1%) underwent therapeutic procedures (surgery, catheter interventions), of whom 24 (20.2%) died. Of the 95 children surviving therapeutic procedures 54 (56.8%) had their defects completely repaired, while 41 (43.2%) had residual defects or cardiac sequelae, often of minor importance. Of 69 children (19.2%) with persistent untreated defects, 43 (62.3%) had VSD. A chromosomal disorder, various syndromes or extracardiac malformations occurred in 72 children (20%). The study underlines the fact that CHD presents itself in varying degrees of severity, including a high neonatal mortality rate as well as a high rate of spontaneous cure.