Objective: Our aim is to evaluate using hypertonic saline 3% as dehydrating measure in supratorial tumors resection compared with the traditional use of mannitol 20%. The study included 40 patients with a mean age of 25‐58 years ASA I, II undergoing elective supratentorial craniotomy.After induction of general anesthesia (GA) and urinarycatheterization patients were randomly assigned into twoequal groups (each 20 patients). Mannitol (m) group received 200 ml of mannitol 20%, and hypertonic saline (HS) groupreceived 200 ml hypertonic saline 3%. Heart (HR) and mean arterial pressure (MAP) were recorded after induction ofanesthesia, at skull‐ pin insertion, at skin incision, at 1 hr hole at bone flap elevation, at dural incision at dural closure, at skilclosure on admission to postanesthesia care unit (PACU) every h for 6 hours after ICU admission. Intaracranial 1pressure (ICP) was measured at the above mentioned time. Points cerebal perfusion pressure (CPP) was also calculatedEffects on serum asmolarity hematocrit NA were assessed.Results: MAP and HR showed insignificant differences betweengroups. ICP measurements showed significant decreaserelative to baseline after infusion but did not show anysignificant difference between groups.Conclusion: Usage of hypertonic saline 3% is as efficient asmannitol 20% in reduction of ICP maintaining hemodynamics of the patients with transient effects on electrolytes an acid‐basestatus of the patients