A study was made of the types of anesthesia chosen by the anesthesiologists in 100 cases of penetrating wounds of the heart. The most urgent problems were hypotension due to loss of blood, cardiac tamponade due to hemopericardium, and hypoxia due to pneumothorax or hemothorax. In 47 cases no preoperative medicaments were given; nearly all the other patients received atropine or scopolamine. Cyclopropane, with or without other anesthetics, was used in 74 cases because of the quick, quiet induction it afforded. Intubation of the trachea was done as soon as possible, to assist respiration, and then thoracotomy in order to relieve cardiac tamponade or to stop hemorrhage. Four patients who were moribund when admitted to the hospital received only oxygen, and there were eight other deaths. The average length of hospitalization for this group of patients was 14 days.