Clinical utility of aspirin (acetylsalicylic acid, ASA) is one of the more important issues in the primary and secondary prevention of cardiovascular disease. The present paper provides analysis of aspirin history, mechanisms of its antiplatelet activity, and expediency of the use of low- and high-dose aspirin in the groups including patients after myocardial revascularization, and requiring secondary prevention of stroke. Also gender-specific aspirin properties were mentioned, highlighting the especially important role of aspirin in women at the age of >65 years, and its utility in all women, irrespectively of age, and those who are at high risk of cardiovascular disease, including atherosclerosis-related cardiovascular disease. Moreover, the mechanisms of aspirin resistance, characterized by inability of aspirin to prevent thromboembolic complications or inadequate platelet inhibition showed in laboratory results, were mentioned. Prevalence of resistance in aspirin-treated patients is estimated to be between 1 and 68%. Stress was also put on the aspirin safety, associated with prophylaxis of peptic ulcer disease, which can be achieved i.e. by the use of the enteric-coated aspirin. This form of aspirin is associated with lower risk of gastrointestinal mucosae damage and bleeding from the gastrointestinal tract. At the end of the article, the importance of the adherence to therapeutic guidelines of aspirin use, including assessment of variation in aspirin bioavailability associated with improper dosing and altered absorption in the gastrointestinal tract, was stressed.