The etiology of cardiac allograft vasculopathy is not known, but may be preceded by both endothelial cell and smooth muscle dysfunction of the epicardial coronary arteries. We here report a case of acute, reversible coronary artery vasospasm which caused a myocardial infarction in a cardiac transplant recipient. The patient had a complex post-transplant course, including an episode of severe vascular rejection several months before this presentation. Interestingly, the event was captured in its early stages because the patient presented with chest pain: a rare event because of the denervation of the transplanted heart. Our ability to document the etiology of this patient's myocardial infarction supports the concept that cardiac allograft vasculopathy is a progressive disease that, in its early stages, may include a reversible component of abnormal vasoreactivity.