BACKGROUND: The role of antithrombotic therapy in prognosticating patients with coronary heart disease (CHD) is crucial. This study evaluated the Knowledge, Attitude, and Practice (KAP) of CHD patients regarding antithrombotic therapy. METHODS: This cross-sectional study distributed questionnaires to collect data. Participants' demographic information was recorded, and their KAP scores were assessed. The Self-Efficacy for Appropriate Medication Use Scale (SEAMS) measured self-efficacy. RESULTS: The study comprised 639 individuals. The median scores were as follows: knowledge score 8 (IQR 6-10), attitude score 25 (IQR 23-27), and practice score 22 (IQR 20-24). Notably, up to 70% of patients incorrectly responded to questions about dosage and administration of antithrombotic agents, and approximately 40% lacked awareness of the treatment's importance and side effects. Low practice scores were independently linked to rural residence, low attitude scores, and poor self-efficacy. Furthermore, Predictive factors for low self-efficacy included being underweight, having a high family income, a short medical history, and low attitude scores. CONCLUSIONS: The surveyed patients with CHD exhibited good attitudes, practices, and self-efficacy but demonstrated only median knowledge levels toward antithrombotic therapy, especially about the importance and precautions associated with antithrombotic treatment. Therefore, initiatives aimed at improving adherence to antithrombotic therapy among CHD patients should focus on the knowledge gaps, especially for patients in rural areas. Improving the patient KAP could help improve the physician-patient interaction.