We report on two cases of successful surgical repair of cardiac injury: one involving a left ventricular stab injury and the other a blunt rupture of the right atrium. Each patient underwent emergency surgical repair, the former via left anterolateral thoracotomy and the latter via median sternotomy, following pericardial drainage tube insertion from the subxiphoid area. The operative approach was chosen according to the color of drained blood, i.e., arterial bleeding indicated left anterolateral thoracotomy, while venous bleeding indicated median sternotomy. We conclude that pericardial drainage via the subxiphoid approach prior to induction of anesthesia is an easy and useful technique to perform, not only to release cardiac tamponade but to determine the operative approach in patients suffering from cardiac tamponade following cardiac injury.