Arterio-ureteral fistulas (AUFs), which are relatively rare but potentially life-threatening, require prompt diagnosis and treatment. We reported a case of AUFs following robot-assisted laparoscopic radical cystectomy (RARC) with extended pelvic lymph node dissection and ileal conduit urinary diversion for muscle-invasive bladder cancer, which resulted in massive hemorrhage. Urine leaked from the anastomosis between the ureter, and the end of the ileal conduit was infected, which resulted in an AUF between the pseudoaneurysm of the right common iliac artery and the ureter. The AUF was managed successfully by vascular intervention with an arterial stent graft.