BACKGROUND AND AIMS: The prevalence of coronary chronic total occlusions (CTO) among patients with chronic coronary syndrome (CCS) and their associations with clinical factors have received limited study. We analyzed a national database registry to determine the prevalence, location, and parameters associated with coronary CTOs. METHODS: We identified all CCS patients without prior coronary artery bypass graft surgery (CABG) who underwent coronary angiography in the Persian CardioVascular Disease Registry (PCVDR). We compared the baseline demographics and characteristics of patients with vs. without at least one CTO lesion. We used logistic regression analysis to identify parameters associated with coronary CTOs. RESULTS: Among the 40,161 patients with CCS who underwent coronary angiography between March 2019 and December 2023, 6805 (17.86%) had at least one CTO. CTO patients were significantly older (64.43 ± 8.96 years vs. 62.64 ± 9.54 years, CONCLUSION: Approximately 1 in 5 CCS patients without prior CABG undergoing coronary angiography in this national database registry had a CTO. Advanced age, male gender, history of smoking, diabetes mellitus, and dyslipidemia were associated with higher likelihood of coronary CTOs.