The laser palliation of patients with unresectable lung cancer has an acceptable complication rate. Perforation, bleeding, and pneumothorax are the main complications described. Cardiovascular morbidity has been reported to be 1% in six surgical series and has been attributed to general anesthetics or hypoxia. However, one very recent anesthesia study described a 25% incidence, and two case reports inferred an air embolism. We reviewed 62 patients who have undergone 111 treatments for endobronchial carcinoma. Eight manifested perioperative cardiac or cerebral events. Five of the eight developed bradycardia; four experienced progression to intraoperative cardiac arrest. Other electrocardiographic abnormalities appeared and resolved within 24 hours. Four patients developed stroke and electrocardiographic changes. Two of these resolved spontaneously within 1 month. Early computed tomography in one patient showed intracerebral air. These data indicate that patient disease or hypoxemia is not sufficient to explain intraoperative cardiac and postoperative cerebral changes. Air embolism to the cerebral circulation occurs during laser bronchoscopy. Reduced cooling air flow, return to helium fiber cooling, or reversion to photodynamic therapy is indicated.