Intravenous (IV) administration of tissue plasminogen activator (tPA) given to patients during acute cerebral ischemia according to National Institute of Neurological Disorders and Stroke (NINDS) guidelines improves clinical outcome by 11% to 14%. The success of IV tPA stroke therapy is dependent on several previously reported factors. The authors suggest that the presence of calcification within an embolus may represent an additional important factor. This report describes a patient with an acute stroke secondary to a spontaneous calcific cerebral embolus who had a negative outcome despite receiving proper thrombolytic therapy.