Aspirin is currently recommended by ADA (American Diabetes Association) for the diabetic patients over 40 years of age and without cardiovascular disease. This recommendation is at odds with drug approval for aspirin. The main explanation is the absence of appropriate trials assessing the usefulness of aspirin in such patients. Two assumptions, central to these guidelines are that diabetes is a coronary risk equivalent, and that aspirin benefit/risk ratio is similar in diabetic patients than in coronary disease patients. Unfortunately, vascular risk level is variable in diabetic patients. Patients with new onset diabetes have lower cardiovascular risk than patients with established cardiovascular disease. Smoking habits markedly increase the risk. Benefits may be lower in diabetic patients since aspirin resistance is common in these patients. Haemorrhagic risk may be higher since diabetes is a risk factor for haemorrhagic stroke. Awaiting trial evidence, aspirin therapy should be considered in diabetic patients with a very high risk, such as smokers, patients with long diabetes duration, or atherosclerotic plaques at echography.