BACKGROUND: Adherence to long-term secondary preventive therapies is vital for improving outcomes in patients recovering from acute coronary syndrome (ACS). This study aims to quantify the extent of non-adherence to these therapies in Iraq and identify the main factors contributing to this issue, addressing a research gap in the Eastern Mediterranean region. METHODS: This cross-sectional study was conducted from June 2023 to March 2024 in Cardiology Ward of Azadi Teaching Hospital and the Duhok Heart Center, Duhok, Kurdistan Region of Iraq, enrolling 400 patients diagnosed with (ACS). The Adherence in Chronic Diseases Scale (ACDS) was utilized to categorize patients into high, intermediate, or low adherence groups. The study questionnaire comprised three sections including clinicodemographic data, adherence assessment based on the ACDS, and patient-reported reasons for non-adherence. RESULTS: The study revealed that the mean age of the participants was 65.78 ± 11.8 years. Within the sample, 24% reported low adherence, 39% reported medium adherence, and only 37% exhibited high adherence. Significant associations were observed between low adherence and older age ( CONCLUSION: The study concludes that a substantial portion of ACS patients in Iraq show low adherence to secondary preventive therapies. To increase adherence among patients with ACS, strategies should be developed to improve medication adherence and promote healthy behaviors simultaneously, Forgetfulness and lack of follow-up are the primary reasons for non-adherence.