Intramural hematoma in major coronary epicardial vessels is a rare cause of chest pain. Afflicted individuals may present with acute coronary syndrome (ACS) or even sudden cardiac death. Spontaneous, isolated intramural hematoma may occur in the absence of associated intimal dissection. In this situation, lesions may be angiographically indistinguishable from ruptured atherosclerotic plaque. Intravascular ultrasound is important in the accurate diagnosis of isolated intramural hematoma. Although coronary stenting may be required in the presence of ongoing ischemia, intramural hematoma may be successfully managed medically. We describe the case of a middle-aged woman who presented with ACS due to an intramural hematoma and discuss the diagnosis and management of this rare illness.