Induction of anaesthesia in intracranial surgery, especially for vascular diseases, must minimize haemodynamic changes: blood pressure and cerebral blood flow must not be increased to a high degree. Our work compares increases in blood pressure and in the speed of cerebral blood flow during endotracheal intubation in two groups of patients, who received propofol or thiopentone for the induction of anaesthesia. We studied 30 patients, without intracranial diseases, who underwent lumbar slipped disk surgery. Half of the patients received thiopentone and curare before intubation and the other half propofol and curare. Increase in blood pressure after intubation was lower with propofol than with thiopentone in a statistically significant way. Also the increase in the speed of cerebral blood flow, measured with doppler technique, was lower when induction with propofol was used, though not statistically relevant.