Backgroud and Aims: The advent of ultrasound guided techniques has led to increased interest in Transversus Abdominis Plane block (TAP) for abdominal surgeries. Recently the transversus abdominis plane block (TAP block) has been used as a part of multimodal analgesia with promising results. The oblique subcostal approach (OSTAP block), a variant of the TAP block, produces reliable supra umbilical analgesia. This study aimed to compare the efficacy of ultrasound guided OSTAP block with portsite infiltration in laparoscopic cholecystectomy for postoperative analgesia. Methods: Eighty patients scheduled to undergo laparoscopic cholecystectomy under general anaesthesia were divided into two groups: Group A (n=40) patients received oblique subcostal transversus abdominis plane block with 15 ml of 0.25% bupivacaine on each side and Group B (n=40) received local portsite wound infiltration with 30 ml of 0.25% bupivacaine in all four ports. The primary and secondary outcome variables were postoperative pain relief, duration of analgesia, rescue analgesic requirement and any side effects, which were noted. Results: The postoperative VAS scores were significantly lower in group A (OSTAP) compared to group B (Portsite) at 0, 1, 2 and 3 hours postoperatively. OSTAP block resulted in longer duration of analgesia as compared to portsite infiltration. The mean duration of analgesia recorded in OSTAP group A was 5.68±2.08 hours and in portsite infiltration group B was 2.53±1.19 hours. The total dosage demand for rescue analgesia in first 24 hours was also less in the study group A compared to group B i.e 91.87±31.71mg of diclofenac sodium in group A and in group B was 135.01±34.80 mg. Postoperative nausea vomiting score though was less in group A than in group B but there was no statistically significant difference in between the groups. Conclusion: The results suggest that the use of Ultrasound guided bilateral oblique subcostal transversus abdominis plane block reduces postoperative pain scores, prolongs the duration of analgesia and decreases demand for rescue analgesia without causing any adverse effects in comparison to portsite infiltration.