A 52-year-old man consulted his doctor with complaints of lower abdominal pain for 1 year. Blood and urine analyses showed urinary occult blood but no anemia or elevated tumor markers. Computed tomography and magnetic resonance imaging revealed a 75 × 62 mm retroperitoneal tumor with no metastasis. The tumor was in contact with the left common iliac artery and the left ureter was compressed, resulting in hydronephrosis. The patient was referred to our hospital after the placement of a left ureteral stent. Biopsy was difficult due to tumor localization ; therefore, retroperitoneal tumor resection was performed. Histopathology revealed a pleomorphic rhabdomyosarcoma. There was a localized recurrence after 3 years. We performed tumor resection and postoperative radiation therapy at 50 Gy. The clinical course was favorable, with no recurrence or metastasis for 6 years since the first surgery.