Planned surgery for abdominal aortic aneurysms carries a low mortality (0-2%). Ultrasound examination of the abdomen can identify the aorta in 92% of patients. We have undertaken a study of the asymptomatic population based on a general practice (Family Doctor) register. The long term aims of this survey will be to identify a high risk group in which surgery is indicated, a low risk group were surgery can be avoided and a group of aneurysms in whom emergency surgery is contra-indicated. Arguments are put forward against improved treatment of aneurysms as emergencies as a way of improving overall survival and against the treatment of all cases detected by ultrasound as planned procedures. The current methods of selecting high risk cases are criticised and a possible method of selecting cases for planned surgery, based on screening and ultrasound follow-up is put forward. The advantages and disadvantages of an ultrasound screening programme are discussed.