Aim: This work aims to compare the postoperative analgesic effects and side effects of Dexamethasone orNeostigmine that added to levobupivacaine. Patient and Methods: Eighty patients aged between 20–80 years with ASA I– II who were scheduled for perianal surgeries under spinal anesthesia were enrolled in our study after written informed consent and approval of ethical committee; This Study was conducted in Sohag University Hospitals from August 2016 to March 2017. Patients Were divided into 2 equal groups:- (Group A) 40 patients received 100μg Neostigmine in 0.5 ml normal saline added to2.5ml volume of levobupivacaine.- (Group B) 40 patients received 4mg dexamethasone added to 2.5ml volume of levobupivacaine. Under complete aseptic conditions, spinal anesthesia was carried out in the sitting position, at level (L3-4 or L4-5). After a free flow of cerebrospinal fluid was confirmed, each patient received one of the coded spinal solutions (GA or GB). After administration; the patients stilled in sitting potion for 10 minutes then patients were turned into the supine position. Patients were monitored for: Heart rate; NIBP and Oxygen Saturation. Patients were observed for onset, duration of sensory block and motor block; In the post-anesthesia care unit (PACU), the patients were asked to assess their level of pain based on a visual analog scale (VAS). Complications also were observed .
                     Results: Dexamethasone had a faster Onset of sensory block onset than Neostigmine; Dexamethasone had a longer duration of regard Duration of motor block than Neostigmine; Neostigmine group had a longer analgesic effect stayed longer than Dexamethasone group .No Significant difference Between Two groups in rate of Complications ; Hypotension and Bradycardia were the most frequent complications in the two groups .Conclusion: the addition of  Dexamethasone 4mg Neostigmine 100μg to intrathecally injected Levobupivacaine improved the effect of Levobupivacaine and the postoperative analgesic effect and duration