A 53-year-old man presented with melena 3 months after microwave ablation of a renal mass. Esophago-gastroduodenoscopy and radiological imaging revealed that a fistulous tract extended from the duodenum to the right kidney. The patient had a hemorrhage that originated from a branch of the renal artery and bled through the fistulous tract into the duodenal lumen. Angiography was used in the successful coiling of the bleeding vessel to control the bleeding. Consideration of a fistulous tract as a source of gastrointestinal bleeding should be included in a clinician's differential diagnosis when dealing with patients who had a recent ablative procedure.