Objective: Sufficient control of intraoperative bleeding in functional endoscopic sinus surgery is essential for obtaining adequate surgical results. The necessity of hypotensive anesthetic techniques is a controversial topic among anesthesiologists and ENT-surgeons. This prospective, randomized study compared N2O-supplemented intravenous anesthesia with propofol and fentanyl or sufentanil with respect to hemodynamic reactions, endocrine stress response, blood loss and surgical conditions, and recovery. Methods: After obtaining informed consent, 32 patients undergoing endoscopic sinus procedures were anesthetized with N2O, propofol, and fentanyl or sufentanil (dosage ratio fentanyl : sufentanil = 7:1). Arterial blood pressure was measured via an arterial line, blood samples for ACTH, AVP, and cortisol were obtained pre-, intra-, and post-operatively, and a psychomotor function test was conducted pre- and postoperatively. The ENT-surgeon estimated the dryness of the surgical field on a numeric scale ranging from 1 to 5, and intraoperative blood loss was measured. Results: Hemodynamic reactions to surgical simulation were blunted more sufficiently in the sufentanil group. Surgical conditions were satisfactory in all patients, but significantly better in the sufentanil group; differences in blood loss did not prove statistically significant. The endocrine stress response was efficiently blunted without significant differences between the groups. Postoperative psychomotor testing showed better recovery in the sufentanil group. Conclusions: N2O-supplemented intravenous anesthesia is suitable for functional endoscopic sinus procedure without any further need for induced hypotension; sufentanil seems to be superior in regard to hemodynamic stability, surgical conditions, and psychomotor recovery.