Medication nonadherence to dual antiplatelet therapy increases major cardiovascular events. In this study, we investigated patients' post-acute coronary syndrome (ACS) medication adherence to clopidogrel and ticagrelor over a 12-month period. Furthermore, we also examined the factors that may affect medication adherence in this patient population. This study included 509 patients who were scheduled for dual antiplatelet therapy for one year following ACS (October 2018-December 2019). A proportion of days covered (PDC) method, based on a pharmacy database system, was used to determine their medication adherence. Medication adherence was defined as > 80% PDC. No difference was found between clopidogrel and ticagrelor in terms of medication adherence (68.3% vs. 64.6%, p = 0.39). Moreover, higher education levels (B = 3.24, CI: 1.17-8.9, p = 0.023) and percutaneous coronary intervention (PCI) as a revascularization option (B = 0.35, CI: 0.17-0.71, p = 0.004) predicted medication adherence independently. In this research, medication adherence was found to be similar between the clopidogrel and ticagrelor groups. It was also predicted by higher education levels and revascularization with PCI.