Background: There is significant postoperative pain in major gynecological cancer surgery patients. Ultrasound (USG) guided Transversus Abdominis Plane (TAP) block is a novel approach to provide analgesia to anterior abdominal wall. We evaluated the analgesic efficacy of the morphine added to bupivacaine in USG guided TAP block to patients undergoing major gynecologic cancer surgeries in a prospective randomized controlled clinical study. Method: After ethical committee approval, 60 ASA grade I and II adult female patients were included and randomly divided into 2 groups (30 each) to receive either 20ml 0.5% bupivacaine +morphine 0.1mg/kg diluted in 20ml saline (BM group) or 20ml 0.5% bupivacaine alone diluted in 20ml saline (B group) bilaterally in USG guided TAP block. Observation was done for time for first rescue analgesic requirement, total analgesic requirement, VAS score at rest and on movement, hemodynamics and drug related side effects for 24 hours in postoperative period. Results: Time for requirement of first rescue analgesic was significantly longer in BM group 11.20±3.16 hours in comparison to B group 8.10±2.13 hours (p<0.001) Total diclofenac sodium requirement in 24 hrs in BM group was 30.70±10.20mg and in B group was 93.20±20.36 mg (p<0.001). In BM group VAS score at 6, 8, 12hours were significantly lower compared to B group (p<0.001). No significant difference in hemodynamic changes and side effects. Conclusion: The USG guided TAP block using morphine with bupivacaine provided superior postoperative analgesia when compared to bupivacaine alone after major gynecological cancer surgeries without any significant side effects.