Assessing a patient's competence to give informed consent in pre-hospital care is difficult. In the presented case an elderly patient attempted suicide by division of a chronically infected and externalised prosthetic arterial graft. He was able to comprehend his situation and understand the consequences of declining treatment. Without prior knowledge of his medical care and psychological state, however, we did not believe we could fully assess the patient's ability to act in his own best interest. After sedation and resuscitation he was transferred to hospital. This case report discusses a unique method of suicide and the challenge of obtaining valid consent in prehospital care.