Background:Transversus abdominis plane block is regional anaesthesia technique that provides analgesia to the parietal peritoneum as well as skin and muscles of the anterior abdominal wall.Magnesium is N-methyl D-aspartate receptor and physiological calcium antagonist.Dexamethasone is a potent glucocorticoid,has anti-inflammatory as well as analgesic properties. Objectives: To compare the duration of postoperative analgesia,time of administration of first rescue analgesia,systemic side effects of Bupivacaine with Magnesium sulphate and Dexamethasone using Transversus abdominis plane block. Methods: After approval of ethical committee and informed written consent A total of Sixty ASA grade I and II patients aged between 18-60 years undergoing lower abdominal surgeries were randomnly allocated to receive TAP block and divided into two groups of 30 each . Group BD received 20ml of 0.25% Bupivacaine +2ml(8mg) Dexamethasone , Group BM received 20ml 0f 0.25% Bupivacaine+1ml of 25% Magnesium sulphate(250mg)+1ml of normal saline respectively.Heart rate,mean arterial pressure,VAS score,time for first rescue analgesia and side effects were recorded postoperatively. Analgesia was given when VAS score was more than 4. Results: The postoperative visual analogue scale scores was significantly less in group BM.Time for first rescue analgesia was more in group BM compared to group BD without any systemic side effects . Conclusion:Administration of Magnesium sulphate with Bupivacaine reduces postoperative pain scores, prolongs the postoperative analgesia compared with Dexamethasone without any systemic side effects.