Pyelocystography on a 61-year-old man with a ureteral stone incidentally revealed the inguinal bladder hernia. He had no complaint of urinary disturbances. During the operation for the hernia, we could not find the bladder without transurethral saline instillation; only the intestine covered with peritoneum was in sight. Utility of preoperative cystography on the cases of inguinal hernia is discussed.