Steven-Johnson syndrome (SJS) is a rare but serious mucocutaneous reaction to medications. We present a rare case of SJS developing after antibiotic administration for a lower respiratory tract infection and whose inpatient course was complicated with an acute ST-segment elevation myocardial infarction (MI). The laboratory findings revealed thrombocytosis which was possibly reactive and explained the underlying pathophysiology of the thrombus formation seen in the coronary artery. Stenting and aspiration of thrombus was performed. This case illustrates a possibly rare association between SJS and MI.