The study was aimed at investigating cell hemostasis parameters in acute coronary syndrome (ACS), and comparing the effects of various antiaggregant medications (clopidogrel, aspirin, or their combination) on platelet (PL) and red blood cell (RBC) aggregation activity. In total, 98 ACS patients were divided into groups, according to the antiaggregant therapy received. At Days 3-4 and 6-7, PL aggregation activity and RBC morphology and function were assessed. Antiaggregant therapy was highly effective among those receiving combined treatment, with minimal PL aggregation and maximal RBC morphology improvement (high prevalence of discocytes and reversibly deformed RBC) observed as early as Day 3 and further increasing by Day 7. All three variants of antiaggregant therapy were significantly effective, but Clopidogrel, especially in combination with aspirin, demonstrated the best effect. Combined therapy (clopidogrel and aspirin) improved cell hemostasis parameters, which could be linked to better aggregation inhibition due to different therapeutic targets for these two agents