Although aspirin is effective in the treatment of acute coronary syndrome and in the secondary prevention of cardiovascular disease among both men and women, its use in primary prevention remains controversial. The gender-specific meta-analysis demonstrates that the specific types of benefit of aspirin therapy differ between women and men in primary prevention. For primary prevention of cardiovascular disease in women, aspirin therapy significantly reduced the risk of the composite of cardiovascular events primarily by its effect on reducing the risk of stroke. In contrast, in men; aspirin therapy significantly reduced the risk of the composite of cardiovascular events predominantly by reducing the risk of myocardial infarction. The reasons for any sex-based differences in the efficacy of aspirin for primary prevention are unclear and require further exploration.