Abstract Background: Laparoscopic sleeve gastrectomy is the gold standard option for the management of morbid obesity, it is a less invasive procedure with better cosmetic results and shorter operative time and hospital stay. Moreover, the current body of evidence shows that laparoscopic interventions are generally associated with less post-operative pain and analgesic requirements. Aim of Study: To compare the efficacy and safety of intraperitoneal levobupivacaine, and/or magnesium sulphate in different combinations for post-operative pain relief in patients undergoing laparoscopic sleeve gastrectomy. Methods: This is double blind prospective randomized clinical trial set at Ain Shams University Hospitals over a period of 7 months from February to September 2020 on 60 patients who were scheduled to undergo laparoscopic sleeve gastrectomy at Ain Shams University Hospitals. 60 patients were divided into three groups: Group A included patients received intraperitoneal instillation of 30ml of 0.25% Lev-obupivacaine alone, group B included patients received intra-peritoneal instillation of 30ml Magnesium Sulphate 10% alone and Group C included patients received intraperitoneal instil-lation of 15ml Magnesium Sulfate 10% plus 15ml of 0.25% Levobupivacaine to a total volume of 30ml. Results: The average Time to 1st dose of post-operative analgesia demand was also the longest in LevMg group compared to Mg group and Lev group (8.75±4.51 hours compared to 1.40±0.50 hours and 4.95±1.76 hours respectively) which was also highly significant. When total analgesia consumption in 24 hours was analysed, LevMg group had 35.00±26.66mg, Mg group had 136.50±19.27mg and Lev group 87.00±33.73 mg of Pethidine consumption which was highly significant Bupivacaine group had mild tomoderate pain and most of the patients in bupivacaineplus magnesium sulphate group had mild pain in first 24 hours of surgery. Conclusion: Intraperitoneal combination of levobuivacaine and maghnesium sulphate is more effective than levobupiavacaine or maghnesium sulphae alone for post-operative pain after laparscopic sleeve gastrectomy.