Purpose: The purpose of this study was to elucidate the relationship between readiness to quit smoking and smoking cessation, and identify factors associated with smoking cessation in smokers with ischemic heart disease post-coronary angiography (CAG). Methods: This descriptive study was conducted between December 1, 2020 and May 14, 2021 at a P hospital, Busan. A total of 164 subjects completed the questionnaire including general characteristics, coronary artery disease characteristics, readiness to quit smoking, and smoking cession behavior during hospitalization and 4 weeks after discharge. Results: The success rate of smoking cessation after coronary angiography in patients with ischemic heart disease was 49.4% (n=81). In addition, 48.2% of smokers (n=83) attempted smoking cessation after CAG, while 39.8% showed changes in smoking behavior. The readiness to quit smoking was significantly associated with smoking cessation (OR=2.23, p<.005). Conclusion: Readiness to quit smoking was identified as an important factor associated with smoking cessation in patients with cardiovascular disease in this study. In order to increase the smoking cessation rate, it is necessary to strengthen the readiness to quit smoking, followed by a tailored program for smoking cessation in patients with ischemic heart disease.