A 67 year old male patients was anesthetized with halothane for a open reduction of the fractured right femur shaft. The patient was admitted to the emergency room after he had cerebra1 contusion and fracture of the femoral shaft by a traffic, accident. Anesthesia was continued for one and a, half hours without any problem. At around one and a half hours of anesthesia, the patient developed cardiac arrest and resuscitation was performed immediately. The patient's life was saved by resuscitation and the operation was completed without any further problem. At the time of the resuscitation, a tension pneumothorax was recognized but anesthesia was continued with immediate, proper management. Closed thoracotomy was performed at the recovery room after anesthesia and the patient recovered from anesthesia without any other problem.