As part of the Birmingham Community Aneurysm Screening Project, 3500 men aged 65-75 years from 20 urban general practices were invited for aortic ultrasonographic screening at their own general practitioner's surgery; 2669 (76.3 per cent) attended. Compliance rates varied between catchment areas, from 52.1 per cent for inner-city areas to 89.6 per cent for suburbs. Successful aortic imaging was achieved in 97.3 per cent of scans. Aortic diameter > 29 mm occurred in 219 patients (8.4 per cent) and 79 (3.0 per cent) with a diameter > 40 mm were referred for vascular surgical assessment; 140 patients with an aortic diameter of 29-40 mm are currently undergoing follow-up by serial ultrasonographic examinations at intervals of 3 months at their doctor's surgery. Risk factor analysis revealed ischaemic heart disease in 21.9 per cent of men with aneurysm, compared with 11.6 per cent in those without (P < 0.001); 18.3 per cent of men with aneurysm had had a previous myocardial infarction and 13.2 per cent had peripheral vascular disease, compared with 7.4 per cent (P < 0.001) and 8.0 per cent (P < 0.01) respectively of those without. No association was found between aneurysm and hypertension or diabetes. Community-based aortic screening is an inexpensive, effective method of diagnosis of aneurysm, with high compliance from the at-risk cohort of an urban population. Such screening programmes may help to reduce the mortality rate from aortic aneurysm rupture.