Approximately 6000 men die every year from ruptured abdominal aortic aneurysm in England and Wales. Randomised clinical trials and a large pilot study have shown that ultrasound screening of men aged 65 years can prevent about half of these deaths. However, there is a significant perioperative morbidity and mortality from interventions to repair the detected aneurysm. This paper explores the ethical issues of screening men for abdominal aortic aneurysm. It is concluded that a population screening programme for abdominal aortic aneurysm (...) offers a clear balance of good over harm. It is therefore ethically justified, as long as men are given adequate information at every stage of the process. Each man has the right to be properly informed, regardless of whether he accepts the invitation to be screened and, if an aneurysm is detected, whether or not he accepts treatment. (shrink)