Fifty infants and children with acute renal failure were treated with acute peritoneal dialysis between 1987 and 1990. The patients were dialyzed using either a catheter introduced percutaneously over a guide-wire (n = 40) or a Tenckhoff catheter (n = 10). The cause of the acute renal failure was primary renal disease in 17 children, cardiac disease in 19, and trauma/sepsis in 14. Peritoneal dialysis succeeded in controlling metabolic abnormalities, improving fluid balance, and relieving the complications of uremia. The procedure had few major complications. Overall mortality was 50%, reflecting the serious nature of the underlying diseases. We conclude that acute peritoneal dialysis is a safe and effective treatment in most pediatric patients with acute renal failure. Our series of patients treated with acute peritoneal dialysis serves as a basis of comparison for the evaluation of new modalities of therapy in childhood acute renal failure.