The benefit of aspirin as a prophylactic after a thrombotic event was first observed 30 years ago. Its use after coronary or cerebral thrombosis, and in patients judged to be at increased risk of a thrombotic event, is now virtually mandatory, unless there are signs of intolerance. The present policy in the UK for cardiovascular protection by low-dose aspirin is dependent upon the identification of people at high vascular risk. The policy has had only very limited success, partly owing to the fact that only a relatively small proportion of people with levels of vascular risk factors that would justify aspirin prophylaxis are identified. In fact, it has been demonstrated that the application of accepted guidelines for aspirin prophylaxis to risk factor data in representative UK population samples gives a cost-effective evidence-base for a reasonable extension of prophylaxis to all people aged over approximately 50 years. It is possible that reductions in both dementia and cancer incidence could also follow the wider use of low-dose aspirin but further research on these outcomes is urgently required. The evidence on possible benefits and harm from low-dose aspirin should therefore be publicized widely, and everything possible should be done to stimulate discussion involving the general public. In the end, however, the preservation of health is one's own responsibility and, therefore, people should generally be encouraged to evaluate the evidence on health-promotion measures, including low-dose aspirin, and take responsibility for their own health.