During the past 53 years, 105 patients with Wilms' Tumor have been treated at the Children's Hospital of Buffalo. Prospective and retrospective staging of these cases has allowed comparison with other reported series. All-stage survival improved from 37% with operation alone to 46% with operation and planned radiotherapy. During the past 22 years, with the addition of adjunctive chemotherapy, all-stage survival is now 80% with lesser stage survival approaching 100%. Participation in the cooperative National Wilms' Tumor Study has brought the most effective proven treatment to the patient in the shortest period of time.