From June 1988 to December 1996 heart transplantations were performed in 36 newborns and infants below one year of age. Diagnosis were hypoplastic left heart syndrome (n = 26), endocardial fibroelastosis (n = 4), cardiomyopathy (n = 3), and other complex congenital heart defects (n = 3). Mean waiting time for transplantation was 52 days, the mean donor-recipient bodyweight ratio was 1.8. Seven patients (19%) died after transplantation mainly within the first month after transplantation. The cumulative probability of survival is 79% in all patients. The influence of increasing experience is indicated when patients transplanted from 1988-1993 (n = 15) are compared with transplants from 1994-1996 (n = 21). The overall survival in the first group was 50%, whereas patients transplanted from 1994 showed a probability of survival of 92%. The 1-year survival rate in the later group was 100%. In 20 patients a total of 31 rejection episodes were observed. 2 infants died due to rejection. 71% of all rejections occurred during the first month after transplantation. Renal function was slightly impaired one year after transplantation in all patients without tendency for deterioration in the sequel. The somatic development is normal in nearly all infants and the quality of life is excellent. All infants live at home without any restrictions. Two patients, however, suffer from a neurologic deficit. Until now there is no evidence of coronary vascular disease or malignancy. Heart transplantation is in our opinion a reconsiderable alternative in the treatment of complex cardiac disease and cardiomyopathy in infants.