Direct laryngoscopy and endotracheal intubation is accompanied by mechanical stimulation of the laryngopharynx by sympathetic timulation, as reflected by an increase in heart rate and blood pressure. The purpose of this study is to evaluate effects of certain drugs on blood pressure and heart rate during intubation. We intravenously administered some drugs prior to laryngoscopy and endotracheal intubation in adult patients with ASA class 1-2. Seventy-two patients were devided into four groups as follows: Group 1: Control group (none, n=18). Group 2: Lidocaine only (n=18). Group 3: Lidocaine (1 mg/kg) and d-Tubocurarine (3mg)(n=18). Group 4: Lidocaine (1mg/kg), d-Tubocurarine (3mg) and diazepam (0.1mg/kg)(n=18). Blood pressure, heart rate, mean arterial pressure, rate-pressure product, aterial blood gas were measured before induction, after induction, immediately after intubation and at 1, 2, 3 & 5 minutes after intubation. The results were as follows: 1) There were no significant differences in preinduction values of blood pressure, heart rate, rate-pressure product, arterial blood gas. 2) Systolic blood pressure increased significantly 2 minutes after the intubation in all groups and rapidly returned to the preinduction level in group 4, group 3 and then group 2 in that order compared to group l. 3) Diastolic and mean arterial pressure elevated significantly during intubation and rapidly retur- ned to the preinduction level in group 4, group 3 and then group 2 in that order compared to group l. 4) Heart rate increased significantly after the intubation in all groups and more rapidly returned to the preinduction levels 3 minutes after the intubation in group 4. 5) Rate-pressure product following the intubation was over 15,000 mmHg. beat/min in all groups, and more rapidly decreased 15,000 mmHg. beat/min at 2 minutes after the intubtion in group 4, 5 minutes after the intubation in group 3. 6) pH, PaCO2and PaO2values were within normal range following the intubation in all groups. In conclusion, it is suggested that the administration of lidocaine, d-tubocurarine and diazepam prior to the intubation is ideal for those patients with cardiovascular disease & increased intracranial pressure.