A case of a 30-year-old man who developed a myocardial infarction after self-administering an Epi-Pen for an episode of idiopathic anaphylaxis is reported. The patient had numerous risk factors for coronary artery disease, and it was suspected that epinephrine-induced coronary spasm caused the infarct. The Epi-Pen Junior may be indicated in such adults with numerous risk factors for coronary artery disease who are at risk for recurrent anaphylaxis.