In a 52-year-old man, a spontaneous right tension pneumothorax was associated with transient bradycardia, hypotension and electrocardiogram (ECG) changes consisting of precordial ST elevation suggestive of acute myocardial injury. Immediately after chest tube placement, the ECG reverted to near normal. Serial cardiac enzymes and isoenzymes showed no evidence of myocardial infarction. To our knowledge, this is the first reported case of this association. The ECG changes may be related to the hypotensive state induced by the tension pneumothorax with resulting decreased coronary artery blood flow and myocardial ischemia that resolved without infarction.