Acute elevation of the ST segment in several ECG leads was observed in seven patients with bacterial shock during the course of therapy. Six patients had bacterial pneumonia, one had acute cholecystitis, and none had a previous history of heart disease. At the onset of the ST elevation, all patients were receiving dopamine infusion, which in four of them was inadvertently increased shortly before the ECG changes, the ST elevation was not associated with chest pain, pericardial friction rub, or acute changes in the heart rate, or arterial blood pressure. In four patients the maximum ST elevation was greater than or equal to 5 mm. In each instance the ST segment returned to the isoelectric line within 24 hours, and subsequent development of Q waves or changes in the QRS was not observed. Although the existence of an acute pericarditis or an acute myocarditis as possible causes of the ST elevation cannot be fully ruled out, the sudden onset, prominent magnitude, and brief duration of the ST elevation are perhaps more indicative of an acute ischemic event, possibly related to a transient coronary vasoconstriction induced by the dopamine infusion.