Wilms tumor is one of the most common malignant neoplasms in children. In the last 2 decades the survival rate of children with this disease has dramatically increased. However, in adults, the guideline for its management is less clear. We herein report the prolonged survival of a patient with advanced adult Wilms tumor after treatment with chemotherapy, irradiation and operations. Adult Wilms tumor should be treated aggressively with a well-timed combination of surgery, chemotherapy and radiotherapy (i.e., multimodal treatment), even if the stage of the disease was advanced. Thereby, we suspect that the prognosis of adult Wilms tumor would be markedly improved.