A 32-year-old female was admitted to our hospital with the chief complaint of vaginal discharge of urine. She had undergone radical hysterectomy due to uterine cancer at another hospital by a gynecologic surgeon 5 years earlier. X-ray examination showed a stone-like shadow at the left ureter without hydronephrosis. She was diagnosed with ureterovaginal fistula with the left ureteral stone. Left ureterolithotomy and ureterovesiconeostomy was performed. The stone revealed a foreign body stone originating from the silk worm-gut which had penetrated accidentally the ureter when the vaginal wall was sutured at the previous surgery. Including our case, 15 cases of foreign body stones in the upper urinary tract were found in the Japanese literature and none of them were associated with ureterovaginal fistula.