Acute coronary syndrome (ACS) could be a precious opportunity for patients to reveal concealed diseases other than conventional risk factors for ACS, such as hypertension, dyslipidemia, diabetes mellitus, etc. In the setting of ACS, the intracoronary and systemic prothrombotic environment has led to an increase in the risk of stent thrombosis of which mortality was higher among patients with ACS, especially with the highest mortality in patients with ST elevation myocardial infarction. The some specific conditions which were concealed beyond the cardiovascular pathophysiology except well-known risk factors for ACS and stent thrombosis might involve the onset of ACS. We describe a case of a 64-year-old man who was admitted to intensive care unit for chest pain. This case found the possibility that polycythemia vera with Janus kinase 2 (JAK2) V617F mutation might be a underlying disease of ACS with stent thrombosis, and highlighted the importance of recognizing polycythemia vera with JAK2 V617F mutation as concealed disease for cardiologists. We would like to report and review the relationship between ACS and polycythemia vera with JAK2 V617F mutation.