The objective was to evaluate the clinic interest of the esmolol in the attenuation of the hemodynamic response to suspension microlaryngoscopy (mls). It was a prospective, randomized and double blind study, having included 29 patient ASA II and III, distributed in two groups, having received respectively before laryngoscopy: group A (n = 15), esmolol in intravenous (i.v.) at the dose of 150 micrograms.kg-1 and DS group (n = 14), 10 ml of normal saline at 0.9%. Has been achieved a general anaesthesia i.v. based on propofol, fentanyl and atracurium. After tracheal intubation, it has been assured an artificial ventilation. The two groups were comparable for the demographic and anesthetic characteristics. A significant decrease of the mean arterial pressure (-11%) and of the prp (product systolic arterial pressure heart rate) have been raised during the mls, in the group esmolol, whereas the variations of the cardiac frequency were comparable. In order to assure a better hemodynamic control during the mls, it seems important, in addition to the adjustment of the recommended dose of esmolol, to cover the whole duration of the endoscopic act by a continuous drip.