The objective was to quantify the effect of intravenous (i.v) propofol on middle cerebral artery flow velocities (MCA–FV) and its derived parameters in patients undergoing surgery for intracranial tumors. Forty patients aged between 15 to 70 years, of either sex, received 1 to 2.5 mg/kg i.v. propofol during induction of anaesthesia. Pulse rate, mean arterial pressures, end tidal carbon dioxide and FV on the non–tumour side (peak systolic, diastolic and mean) were measured at preinduction, and at 1, 3, 5, 10 and 30 min after induction. The pulsatility (PI) and resistivity (RI) indices and transient hyperemic response ratio (THHR) were derived and compared with their preinduction values. Propofol induced a fall in MCA–FV for peak systolic velocities (26.6%) and a diastolic velocities (38%) increase in PI (14.2%), with no significant change in RI. THHR ranged from 1.38 preinduction to 1.31 post induction. Hence propofol decreases FV without affecting cerebral autoregulation.