Abstract: Aim: To examine the effects of ASA on serum nitric oxide (NO), asymmetric dimethylarginine (ADMA), and homocysteine levels in healthy volunteers. Materials and methods: Totally, 26 apparently healthy volunteers were enrolled in the study. Of the participants, 13 (5F, 8M) received 100 mg of ASA daily and 13 (5F, 8M) received 150 mg of ASA daily for 2 months. Serum NO, ADMA, and homocysteine levels were measured before and 1 and 2 months after ASA treatment Serum NO, ADMA, and homocysteine levels were measured before and 1 and 2 months after ASA treatment. Results: ADMA levels of the group receiving 150 mg of ASA were significantly reduced after 2 months of treatment (P < 0.05). NO levels of both groups were slightly but not significantly increased and homocysteine levels of both groups were slightly reduced after ASA treatment compared to the baseline values. Conclusion: Our findings indicate that ASA treatment reduces ADMA levels dose and time dependently, a beneficial effect that may contribute to the prevention of cardiovascular diseases.