This review examines the assumptions underlying the calls for a national screening programme for aneurysms. It concludes that on the basis of published evidence, many of the necessary criteria for any putative screening programme are not met for this disease. Although the disease is an important cause of death, and a screening method is available, we lack basic knowledge about the natural history of the disease, especially small aneurysms, and about the cost-effectiveness of a screening programme. In particular, the treatment is an operation which, nationwide, carries a high mortality and is likely to be unacceptable to many patients. The consequences of such a programme would be to diagnose many small aneurysms, for which the best treatment remains unclear, and which will engender much unnecessary anxiety among patients so diagnosed.