An old bed-rest patient with subarachnoid hemorrhage in a chronic stage was complicated with a large sacral pressure ulcer with chronic infection and perianal fistula. This chronic intractable pressure ulcer was shrinking by biweekly tank bathing with hot spring water, and finally, about a year after the start of hot spring tank bathing, the pressure ulcer was completely closed and healed. Thus, hot spring bathing possibly helps the wound-healing process even in intractable cases of pressure ulcer with chronic infection and/or fistula.