Right ventricular infarction frequently occurs in the setting of infarction of the inferior wall of the left ventricle. Although there are several protective mechanisms that may limit the size of the infarction, right ventricular damage can result in right ventricular failure and cardiogenic shock. ECG manifestations of right ventricular infarction can facilitate the early recognition of this syndrome. The standard 12-lead ECG may provide some evidence of infarction of the right ventricle. ST-segment elevation in right precordial leads, however, is far more reliable in establishing a diagnosis. These leads should be recorded immediately if the standard 12-lead ECG reveals an acute inferior wall MI. Continuous ST-segment monitoring may be useful in the early detection of ongoing right ventricular ischemia. ECG markers can aid in the prompt institution of appropriate treatment. It is clear that early recognition of right ventricular infarction can have important diagnostic and therapeutic implications.