BACKGROUND: We evaluated the efficacy and safety of positive pressure ventilation (PPV) with a laryngeal mask airway (LMA), compared with an endotracheal tube (ETT) during a laparoscopic cholecystectomy. METHODS: Sixty six, ASA I II adults scheduled for an elective laparoscopic cholecystectomy were randomly assigned to LMA or ETT. Anesthesia was induced with fentanyl 2ng/kg, lidocaine 0.5 mg/kg and propofol 2 mg/kg and maintained with a continuous infusion of propofol 6 - 12 mg/kg/h in 67% N2O, atracurium and fentanyl. An ETT or LMA was placed with atracurium 0.5 mg/kg. Respiratory and hemodynamic parameters were measured before and after intraabdominal CO2 insufflation. The surgeon assessed the degree of change in gastric distension under laparoscope. RESULTS: Oxygen saturation, end-tidal CO2, peak inspiratory pressure, expiratory tidal volume and compliance of the respiratory system didn't differ between both groups. Blood pressure and heart rate were lower in the LMA group than in the ETT group only at 5 min after induction (P < 0.05). The maintenance dose of propofol, fentanyl and atracurium were similar in both groups. Degree of change in gastric distension were similar in both groups. The LMA resulted in less coughing after removal than did the ETT (P < 0.05). CONCLUSIONS: PPV with LMA permits adequate pulmonary ventilation and hemodynamic stability during laparoscopic cholecystectomy. Gastric distension occurs with similar frequency in LMA or ETT.