BACKGROUND: Laryngoscopy and tracheal intubation for general anesthesia are potent stimuli to the cardiovascular system due to sympathetic stimulation. The aim of this study was to compare the hemodynamic responses with different administration routes of lidocaine on blood pressure and heart rate changes associated with tracheal intubation. METHODS: Sixty patients were randomly assigned to spray group (Group 1, n=20) received 10% lidocaine 1.5 mg/kg spray to intratracheally immediately before tracheal intubation, IV group (Group 2, n=20) received 2% lidocaine 1.5 mg/kg intravenously before 90 sec tracheal intubation and control group (Group 3, n=20). Anesthesia was induced with thiopental 5 mg/kg IV, vecuronium 0.1 mg/kg and 50% N2O-O2- 2vol % enflurane. After 5 minutes, tracheal intubation was performed. Mean arterial pressure and heart rate were measured at preintubation and immediately postintubation, 1, 3, 5 mins after tracheal intubation. RESULTS:The differences of mean arterial pressure which were measured at preintubation and immediately postintubation and 1 minute after intubation in group 1 were significantly lower than those in other group (p<0.05). The differences of heart rate which measured at preintubation and 1 minute after intubation were lower than those in group 3 (p<0.05). CONCLUSIONS: For the suppression of sympathetic stimulation following tracheal intubation, 10% lidocaine spray to the laryngotrachea is an effective method to suppress cardiovascular response.