A 53-year-old man with a known allergy to metamizole presented for acute gonalgia, receiving metamizole by mistake. He suffers a severe allergy reaction accompanied by chest pain and signs of acute lower myocardial infarction, which subsides with treatment of anaphylactic shock and fibrinolysis, without observing intracoronary thrombus or signs of complication of atherosclerotic plaque. Keywords: Kounis syndrome; Allergic myocardial infarction; Myocardial infarction with normal coronary arteries.