A 43-year-old woman suffered clinical brain death after severe head injury. The patient met the criteria for the diagnosis of clinical brain death on Day 3. Aggressive hemodynamic and respiratory managements coupled with triple hormone therapy were performed at the family’s request, resulting in continued cardiac activity for a prolonged period. Spinal reflexes and automatisms were observed until cardiac arrest. Ventilatory support was discontinued on Day 168, when cardiac death was confirmed, and her kidneys and eyeballs were removed for transplantation. The patient survived for 165 days after the diagnosis of clinical brain death, which is an extremely prolonged period of somatic support for an adult patient after brain death. An extensive and informed discussion on the end-of-life treatment of clinically brain-dead patients is urgently required in Japan to establish treatment guidelines for such patients.