A 37-year-old male, who at the age of 8 years had been treated for right-sided Wilms' tumor with nephrectomy, radiotherapy, and chemotherapy, presented with noncirrhotic portal hypertension (NCPH), grade 2 esophageal varices, and ascites. A CT scan demonstrated hypoplasia of liver segments 2 and 3. A liver biopsy showed portal tract fibrosis without cirrhosis, with histological features of NCPH. Liver vein catheterization showed a normal portal pressure gradient of 5 mm Hg while spleen to hepatic vein pressure was 29 mm Hg. NCPH after therapy for Wilms' tumor is described in children within the first few years after treatment. This is the first case report in which the patient first presented symptoms as an adult, many years after cancer treatment.