Hypereosinophilic syndrome (HES) is a rare, multisystem, heterogeneous syndrome, characterized by a sustained overproduction of eosinophils, and in which eosinophilic infiltration can cause damage to multiple organs. Cardiac involvement is frequent and carries with it a high rate of morbidity and mortality. Presently described is a patient with peripheral eosinophilia who had myocardial infarction at admission and was diagnosed with HES, a literature review, and discussion.