There is general agreement on the efficacy of aspirin treatment in patients with coronary heart disease, but the indications of aspirin in individuals without coronary heart disease are debated. This paper analyses data from the main studies which investigated the usefulness of aspirin in the primary prevention of coronary heart disease. Particular attention is paid to the risks and benefits of aspirin treatment in different clinically relevant subgroups of patients. It is concluded that, according to available information, the use of aspirin must be integrated in a global strategy for the primary prevention of coronary heart disease and should be probable recommended in males older than 50 years old presenting a higher risk of coronary heart disease (due to the number and intensity of risk factors) and low risk of adverse effects.