The hypertonic reaction and pulse increase was studied in 88 males undergoing bronchoscopy under general anaesthesia. 28 patients were below 45 years of age, 60 were above 60 years. In half of the patients prior to introduction of the bronchoscope into the trachea lidocaine was given in a dose 1.5 mg per kg b.w. Differences in circulatory reactions were seen related to age and lidocaine administration. In the group of younger patients tachycardia was observed, in the older patients increased diastolic and systolic pressure. After lidocaine infusion the differences in circulatory reactions between the age groups became nonsignificant. This study suggests that lidocaine has a negative chronotropic reaction especially in younger patients and hypotensive in older.