Twenty episodes of serious gastrointestinal complication occurred in 14 of 85 (16%) consecutive patients less than 17 years old who underwent renal homograft transplantation. These complications consisted of small-bowel obstruction, ulceration, pancreatitis, hepatitis, ascites, and severe gastroenteritis. Only 1 patient died as a consequence of the complication--a much lower mortality rate than that reported for gastrointestinal complications of renal transplantation in adults. Radiographic findings were diagnostic in the majority of cases and aided in the prompt administration of therapy.