Background: The CHA2DS2-VASC score was evaluated as a risk stratification tool used in predicting outcomes in clinical settings other than preventing stroke in patients with atrial fibrillation (AF). But, its use in coronary artery disease patients who recently had percutaneous coronary intervention (PCI) was not thoroughly studied. Aim of work: determining the availability of using CHA2DS2-VASc score as an effective and simple platelet reactivity predictor in acute myocardial infarction (AMI) patients managed with percutaneous coronary intervention. Subjects and methods: Our prospective study included 180 consecutive acute myocardial infarction patients who were submitted to percutaneous coronary intervention and were hospitalized within twelve hours of symptoms onset. They were categorized, according to their CHA2DS2-VASc risk scores, into two groups: low-risk (0–1 score) and high-risk (2–9 score). Following PCI, using light transmittance aggregometry, platelet reactivity was determined utilizing adenosine diphosphate (ADP)-induced platelet aggregation. Results: We found a significant difference between high and low CHA2DS2-VASc score groups regarding sex, BMI, hyperlipidemia, ST-elevation, statins use, and the number of diseased vessels. As regards mean platelet ADP-induced aggregation reactivity, a significant correlation between reduced mean platelet ADP-induced aggregation reactivity and low CHA2DS2-VASc score was detected in comparison to the high score (42.53 ± 16.21 and 50.67 ± 18.1, respectively, and P = 0.002). Conclusion: The CHA2DS2VASc score may be a significant independent platelet reactivity predictor in acute myocardial infarction patients managed with PCI, and thus it can be utilized in assessing the acute stent thrombosis risk in acute myocardial infarction (AMI) patients after  PCI