Chest pain is an important symptom for emergency physicians. It is one of the most common causes for admission in emergency departments. Acute leukemia (AL) rarely causes chest symptoms due to ostalgia, and it is difficult to diagnose leukemia as the cause of chest pain. An 83-year-old woman with no history of trauma presented to the emergency department with a one-day history of severe chest pain. There were no abnormalities on electrocardiography, echocardiography, specific biomarkers for cardiac injury, or contrast computed tomography of the chest and pelvis. The white blood cell count was normal, but the patient had prominent thrombocytopenia with platelets of 68,000/µL, prothrombin time-international normalized ratio (PT-INR) of 1.2, activated partial thromboplastin time (APTT) of 25.3 s, and D-dimer of 73.55 µg/mL. Due to the holiday, blast cells could not be measured on the same day. The next day's examination revealed blast cells in the peripheral blood. The patient was admitted to the hematology department and discharged three months later. This case suggests the need to consider AL in chest pain associated with coagulation abnormalities and thrombocytopenia, regardless of the white blood cell count.