Triple-drug immunosuppression with OKT3 induction is effective rejection prophylaxis in pediatric cardiac allograft recipients. The concerns regarding prevalent lymphoproliferative disease, growth retardation, cytomegalovirus, and other opportunistic infections have not been realized. Since June 1986, 34 pediatric patients, 23 males and 11 females, (age 4 days to 15 years) have undergone orthotopic heart transplantation at our institution. Fifteen patients were less than 6 months old and 13 had type I or II hypoplastic left heart syndrome. There have been four (12%) operative and four (12%) late deaths and a survival rate of 76% after a mean follow-up of 33 months (range, 1 to 82 months). The only deaths attributed to allograft rejection occurred in two newborn recipients (2 and 10 months after surgery) who neither received maintenance steroids nor underwent routine biopsy. The only death from infection (pneumococcus) occurred 6 months after surgery in a 4-year-old patient who was not known to be asplenic. Of the 27 long-term (> 1 year) survivors, 17 (68%) had an average of two rejection episodes during the follow-up period, 10 patients (32%) have been free of graft rejection, and 26 patients (96%) have not experienced a cytomegalovirus infection despite OKT3 induction therapy. Two patients developed lymphoproliferative disease, one of whom was successfully treated by transient reduction of immunosuppression. The other patient died 13 months after transplantation of a lymphoma of the central nervous system. All survivors have demonstrated satisfactory increases in mean height and weight.(ABSTRACT TRUNCATED AT 250 WORDS)