Doxorubicin and anthracycline antineoplastic agents are well known for their myocardial toxicity. This effect, however, is thought to be a direct one on the myocardium as a result of free radical formation and oxidative stress. We present the case of a patient who suffered an acute myocardial infarction during her first infusion of a liposomal formulation of doxorubicin as part of chemotherapy for recurrent breast cancer. To our knowledge, this is the first report of an angiographically proven infarction temporally related to exposure to this chemotherapeutic agent.