Wilms' tumor is the most frquent malignant abdominal tumor in children but is rare in adults. Adult Wiulms' tumor is less than 1% of all wilms' tumor, and has poor prognosis than childhood Wilms' tumor. Wilms' tumor in children classically demonstrate the curative potential of combined modality cancer therapy. However, guide line for management in adult Wilms' tumor is less clear.

We reported a case of adult Wilms' tumor developed in 18 year-old male patient which was presented with right flank pain after slip-down for 1day.