Many infants with hypoplastic left heart syndrome are now treated with heart transplantation. Preoperative or postoperative systemic/renal hypoperfusion occurs frequently, however, resulting in perioperative kidney failure. Of 45 neonates undergoing heart transplantation at our institution, we report on 10 (22%) who required postoperative peritoneal dialysis. Patients' age at transplantation ranged between 1 and 31 (mean, 16.7) days, average weight was 2912 (range, 2140 to 3664) gms. Peritoneal dialysis was started at a mean of 51 hours after transplantation for treatment of anuria (5 patients, 50%), oliguria (3 patients, 30%), fluid overload or hyperkalemia (1 patient each, 10%) and continued for a mean of 101 +/- 90.5 (range, 33 to 270) hours. The value for blood urea nitrogen fell from 46.7 +/- 15.6 mg/dl to 14.3 +/- 10.5 mg/dl, and serum creatinine levels decreased from 2.4 +/- 1.0 mg/dl to 0.6 +/- 0.3 mg/dl throughout peritoneal dialysis. All patients continued to receive cyclosporine during dialysis. Hyperglycemia developed in four patients. Five of 10 patients had ongoing sepsis during dialysis, but only one died while on dialysis (10%). Two patients died late, after peritoneal dialysis was discontinued. Follow-up ranges from 2 months to 5 years. At most recent follow-up, mean creatinine level was 0.5 +/- 0.1 mg/dl. We conclude that aggressive peritoneal dialysis may result in high salvage rates with low morbidity, without the need to discontinue cyclosporine in the setting of neonatal heart transplantation and acute kidney failure.