Cardiovascular diseases (CVDs) represent a huge health burden for older patients with diabetes. Acetylsalicylic acid (ASA) has long been used as a cardioprotective agent in primary and secondary prevention of CVD. However, there are important issues regarding the benefits and risks of ASA therapy in primary prevention of CVDs, for the older group in general and for individuals of all ages with diabetes. In this review, we summarize the benefits and risks related to ASA therapy by outlining the evidence for older patients and for patients with diabetes. There appear to be significant gaps in knowledge. The balance of benefits and risks is not well defined but ASA treatment seems to be unfavorable in many older patients.