The purpose of this retrospective study was to investigate the effect of revised cardiac rehabilitation Clinical Pathways (CPs) on the Cardiac Rehabilitation (CR) participation rate of patients with Myocardial Infarction (MI) undergoing Percutaneous Coronary Intervention (PCI). Methods: We reviewed the electronic medical record of patients who were referred for CR after MI from July 2015 to December 2016. In April 2016, the patient groups were divided into 9-month periods: pre-and post-CP revision. We reduced the mean number of hospital visits for CR and the wait times before starting CR and the first Cardio Pulmonary Exercise (CPX) test. We added a home-based CR program and reinforced the CR liaison nurse's role. The changes in the CR wait time, mean number of hospital visits post-discharge, and participation rates at 1 and 3 months were investigated. Results: Ninety-two patients were recruited from July 2015 to March 2016. Twenty-four (26.1%) participated in CR at 1 month, and 11 (12.0%) were maintained up to 3 months. From April 2016 to December 2016, 107 patients were recruited. Sixty-five (60.7%) participated at 1 month, and 38 (35.5%) were maintained up to 3 months. The mean number of hospital visits was 3.5±0.8 versus 1.9±0.9 in the previous and revised CP groups. The average number of days to the first CPX test after MI was 43.4±17.6 versus 26.3±10.6. Conclusion: Following CP revision, the CR participation rate significantly improved among patients with PCI post-MI. CP revision in terms of inter-physician communication and additional nursing interventions should be considered.