AbstractBackground: Several methods have been used to improvesurgical field clarity and decrease blood loss intraoperative;one of them is the usage of hypotensive anesthesia. Spinesurgery is one of the surgeries that need a clear field and adecreased amount of intraoperative bleeding which can impact on the ability of surgeons.Aim of Study: Current study was designed to evaluate theeffect of propofol versus isoflurane with nitroglycerine onblood loss, operative field clarity, extubation time and effectof both on tissue perfusion.Settings and Design: This study design was a prospectiverandomized controlled double blinded clinical study.Patients and Methods: 80 ASA or II patients undergoingelective spine surgery were randomly assigned to group P (n=40) that received propofol for induction and maintenancewhile group I (n=40) received thiopental for induction andisoflurane for maintenance with nitroglycerine. Heart rate,mean arterial pressure were recorded every 10min, amountof blood loss, grade of operative field clarity, extubation timeand effect of both on liver and kidney function were recorded.Results: Propofol group showed significant decrease inblood loss (p=0.01), better surgical field clarity (p=0.002)and shorter extubation time (p=0.001) than isoflurane groupbut there were no significant changes between the two groupsregarding their effect on tissue perfusion (liver and kidney).Conclusion: Propofol for elective spine surgery improvedsurgical condition and provided faster recovery compared toisoflurane even when we added an antihypertensive drug asnitroglycerine to isoflurane. Both of them had a comparableminor effect on liver and kidney functions.