Tracheal intubation is accompanied by varying degrees of sympathetic stimulation as reflected by increases in heart rate and blood pressure. Several clinical trials to reduce the effects on blood pressure and heart rate by pharmacologic agents such as α and β blockers, calcium channel blockers, narcotics and lidocaine, have been reported. To evaluate the effect of fentanyl and lidocaine on the hemodynamic changes induced by intubation, we administered thiopental 5 mg/kg only (group 1), fentanyl 3 ug/kg with thiopental 4 mg/kg (group 2) or fentanyl 3 ug/kg-lidocaine 1.5 mg/kg with thiopental 4 mg/kg (group 3) for induction of anesthesia, and measured heart rate, systolic pressure, diastolic pressure, mean pressure and rate- pressure products before induction, after induction and at 1, 3, 5, 7 and 10 minutes after intubation. 1) In group 1, intubation caused a significant increase in heart rate (27%), blood pressure (31%) and RPP (64%) at 1 min after intubation, but each paramenter returned to the normal level within 7 min. 2) In group 2, increases in heart rate, blood pressure and RPP with intubation were attenuated by fentanyl. 3) In group 3, the increase in heart rate induced by intubation was abolished by fentanyl-lidocaine, and the pressor effect was more attenuated compared to group 2. These results suggested that a low dose of fentanyl-lidocaine significantly blunts postintubation hypertension and tachycardia when used as an adjunt to thiopental.