Intraoperative hypothermia and hypocapnia had been widely used for brain protection during neurosurgical procedures as both of them provide favorable effects on cerebral circulation and metabolism. Monitoring of cerebral oxygenation during hypothermia with hypocapnia or with normocapnia during neurosurgical procedures using jugular bulb oxygen saturation allows the detection of cerebral hypoperfusion and ischemia. Also monitoring of cerebral metabolism by measuring jugular bulb lactate and pyruvate as proper indices of anaerobic metabolism during neurosurgery during hypothermia with hypocapnia or with normocapnia allows the detection and prevention of cerebral ischemia as well as ensuring cerebral protection during this critical time.In this study we compared 2 groups, group Ι; hypothermia with hypocapnia & group ΙΙ; hypothermia with normocapnia. The results showed that cerebral oxygenation and metabolism were better in group ΙΙ as reflected by ↑SjvO2 and ↓AJDO2 &CORE as well as ↓jugular bulb lactate and pyruvate compared to group Ι. Further studies are needed on a wider scale in various neurosurgical procedures for verification and evaluation of effect of hypothermia & hypocapnia on cerebral oxygenation and metabolism.