A 27-year-old man developed acute myocardial infarction after intravenous amphetamine use. A coronary angiogram showed plaques in the mid-portion of the left anterior descending artery which developed coronary artery spasm after administration of intracoronary ergonovine. The findings in this case suggest that these coronary artery plaques played a role in the endothelial dysfunction resulting from amphetamine use, and that induction of coronary arterial spasm was the likely mechanism of amphetamine-related acute myocardial infarction.