Résumé : Objective: To evaluate the effects of high-frequency jet ventilation (HFJV) applied to both lungs on hemodynamic parameters, oxygenation, and operating conditions during bilateral videothoracoscopic sympathectomy. Design: A prospective, unblinded study. Setting: An ambulatory surgical unit at a university medical center. Participants: 30 patients (11 men, 19 women), ASA status I. Intervention: Bilateral videothoracoscopic sympathectomies were performed using total intravenous anesthesia with propofol, alfentanil, and atracurium, and the patients were ventilated with an oxygen-air mixture using HFJV delivered to both lungs with a Hi-Lo Jet tracheal tube (Mallinckrodt). Measurements and Main Results: Mean total anesthesia time was 55 ± 13 minutes. Hemodynamic parameters remained stable during surgery, although ablation of the sympathetic ganglia induced three incidences of bradycardia (10% of the patients), which were responsive to atropine. Four patients developed oxygen desaturation (Sa O2 < 90%) after the creation of the pneumothorax. Surgical conditions were considered excellent by the surgeons. Concerning postoperative complications, a temporary Horner's syndrome was observed in one patient. Another patient had a mild residual pneumothorax on the first postoperative day that resolved without insertion of a chest tube. Conclusions: It was concluded that HFJV applied to both lungs is an easy and safe anesthetic technique that provides excellent surgical conditions and causes a minor incidence of morbidity.