Acute promyelocytic leukemia (APL) has one of the most favorable prognoses among other leukemia subtypes. However, the major cause of mortality in APL is disseminated intravascular coagulation at the presentation. We present a case of acute myocardial infarction (MI) at the time of APL diagnosis before treatment. The patient suffered from chest pain, sweating and giddiness. He was hypoxic, hypotensive and bradycardic. ECG showed inferior MI. Unfractioned heparin infusion (850 U/h) was started and 5 min after the previous ECG showed total ST resolution. We suggest that in this case, MI was not related to atherosclerotic plaque rupture but related to DIC manifestation.