The long-term results of 1023 adult patients with congenital heart diseases, operated and non-operated, with atrial septal defect (ASD), patent ductus arteriosus (PDA), pulmonary stenosis (PS) and tetralogy of Fallot, were followed for up to 24 years, and the long-term results of operated and non-operated congenital heart diseases were compared. The survival rate of patients with operated isolated ASD was significantly higher than in patients with non-operated isolated ASD, and that of operated patients with VSD associated with other anomalies was also significantly higher than in non-operated VSD patients with such involvement. The survival rate showed no significant difference in the operated and non-operated patients with PDA, PS and tetralogy of Fallot. In all congenital heart diseases, there was a close correlation between the mean pulmonary artery pressure and the mortality rate both in operated and non-operated patients and a marked improvement of physical capacity of operated patients at the time of the last follow-up examination.