Objective: To describe the long-term prognosis after repair of Tetralogy of Fallot with pulmonary stenosis beyond 20 years. Methods: One hundred and eighty five patients underwent corrective repair of Tetralogy of Fallot at Rigshospitalet in Copenhagen between January 1960 and July 1977. Ninety seven patients had undergone a palliative operation prior to Tetralogy of Fallot repair. All the 125 patients who were discharged from the hospital were traced through the population register and the patients alive July 1997 were contacted by mail and/or telephone and questioned about use of medicine, professional status, family status and ability to perform sport activities. Results: Sixty patients died in hospital and 125 patients, 78 males and 47 females, were discharged alive. Among operative survivors, median age at operation was 12.8 years (range 0.4-41 years). Thirteen patients required a reoperation, the main indication was failed VSD closure. There were 16 late cardiac deaths, out of which seven were sudden and unexpected and three were in immediate relation to reoperations. One hundred and nine patients were alive at follow-up. The mean follow-up time was 25.5 years (range 20-38 years). Sixteen percent used cardiac drugs, 89% were, or had been, working normally (all professions from academics to hard manual labors were represented), 53% (64% of women) had given birth after the repair and 51% performed sport activities regularly. No patients were lost to follow-up. Conclusions: The vast majority of the patients seemed to live normal lives 20-37 years after Tetralogy of Fallot repair. Late deaths were cardiac in origin, including sudden death from arrhythmias. The number of late reoperation has been low. Considering the natural history of the disease, Fallot repair has proven to be a beneficial procedure even including the very early experience short after introduction of open heart surgery. (C) 1999 Elsevier Science B.V. All rights reserved.