BACKGROUND: Supraglottic airway devices can be used to maintain stable hemodynamics during intubation, to secure a difficult airway and to administer muscle relaxants at reduced levels for brief operation. We investigated the insertion success rates, hemodynamic stabilities after insertion, intraoperative ventilatory parameters, and postoperative laryngopharyngeal discomforts of three supraglottic airway devices: the ProSealTM laryngeal mask airway (PLMA), the laryngeal tube (LT), and the PAxpressTM (PAX). METHODS: After induction with thiopental 5 mg/kg with fentanyl 1microgram/kg and rocuronuim 0.6 mg/kg as muscle relaxants, manual control ventilation was done with N2O : O2 (1 : 1) and sevoflurane 5-6 vol% for 2 minutes. The supraglottic airway devices were inserted into 94 adult ASA physical status I and II patients. Unblinded observers collected the intraoperative data, and blinded observers collected the postoperative data. RESULTS: The success rates of first-attempts were similar (PLMA: 96.9%, LT: 93.1%, PAX: 96.8%). The time to achieve effective ventilation was shorten for PLMA. Peak inspiratory pressure (PIP) was significant higher for PAX than PLMA. Cuff pressure significantly increased in LT at 60 and 90 minutes after insertion. LT provided the tightest seal for positive ventilation. The incidence of blood-tinged and sore throat was highest for PAX. CONCLUSIONS: These three supraglottic airway devices can be used successfully and effectively without gastric insufflation. We suspected that the incidences of airway complications were proportional to PIP and cuff pressure and that they are dependent upon insertion skill.