A number of recent studies have brought new data and a better understanding of the risk versus benefit of abdominal aortic aneurysm repair. The present evidence indicates that the risk of rupture for non tender aneurysms less than 5 cm is so low that patients can generally be followed by 6 monthly ultrasound and not undergo immediate operation. Surgery should be the method of choice for most patients where the aneurysm is greater than 5 cm.