Background: Perioperative use of magnesium sulfate (MgSO4), dexmedetomidine, have been tried in order to provide beneficial clinical effects during general anesthesia (GA). However, few literature discussed it with varying results. Several clinical researches have showed that usage of MgSO4 infusion was associated with a reduction in anesthetic requirement and postsurgical analgesic consumption during GA.Objective: This study aimed to assess the pharmacologic effects of the use of dexmedetomidine and MgSO4 on anesthetic requirement, intra operative haemodynamics stability and postsurgical analgesic effects on the adequacy of hypotensive anesthesia during transsphenoidal resection of pituitary tumours. Patients and methods: A total of 110 cases were enrolled in this prospective study. They were randomized into 2 groups: Group D (55 cases) that was commenced on dexmedetomidine, and group M (55 cases) which received MgSO4 Results: The mean values of Boezaart score were significantly decreased in Group D in comparison to group M. In addition, isoflurane and propranolol consumption showed a significant decrease in group D. However, blood loss showed no significant difference when comparing the same groups. Group D expressed significantly longer emergence and extubation times compared to Group M. Conclusion: Dexmedetomidine appears to be superior compared to magnesium sulphate in achieving hypotensive anesthesia during pituitary surgery.