Increases in blood pressure and heart rate often seen with laryngoscopy and endotracheal intubation during induction of anesthesia can be dangerous for many patients. In twenty five patients pretreated with ketanserin, a new antihypertensive agent, changes in blood pressure and heart rate were compared with the hemodynamic parameters of twenty untreated patients. Ketanserin 10 mg intravenously was administered prior to induction of anesthesia. Ten mg i.v. ketanserin will not prevent increases in arterial pressure; however the increases in diastolic and mean arterial pressure are significantly lower than these increases in untreated patients.