Objective : An adequate risk stratification protocol is important in cardiac rehabilitation. However, defining this is difficult in patients with myocardial infarction in the early recovery phase, because the maximal exercise testing for determining the stratification cannot be performed in this phase. The purpose of this study was to investigate the usefulness of the risk stratification protocol of the American Association of Cardiovascular and Pulmonary Rehabilitation (AACVPR) based on an index without cardiopulmonary exercise testing. Methods :We investigated 164 patients with ST-elevation myocardial infarction who completed the acute rehabilitation program after percutaneous coronary intervention. Patients were classified into low, moderate, and high-risk groups by the risk stratification,and then we calculated their Thrombolysis in Myocardial Infarction risk score for STEMI (TIMI RS), Global Registry of Acute Coronary Events risk model (GRACE RS), Primary Angioplasty in Myocardial Infarction risk score (PAMI RS), and Zwolle risk score for STEMI (Zwolle RS) which are the major comprehensive risk scores designed for predicting short-term outcome after acute coronary syndromes. We compared the risk scores among the three groups, and we investigated major adverse cardiac events (MACE) during supervised exercise in the early recovery phase. Results : As a result, we found a statistically significant difference between the low-risk group and the high-risk group in all risk scores. In addition, there were no MACE during supervised exercise in this period. Conclusion : This study suggests that, by using the AACVPR risk stratification protocol based on an index without cardiopulmonary exercise testing, it is possible to roughly classify the risk in this phase, and that it is useful for defining safe exercise regimes in patients with ST-elevation myocardial infarction in the early recovery phase.