Background: Supraclavicular block has emerged as reliable alternative to general anaesthesia for upper limb surgery and for providing post operative analgesia. Availability and use of nerve stimulator and now ultrasound in anaesthesia, making regional anaesthesia techniques more safe and more successful than blind technique. Buprenorphine as an adjuvant to local anaesthetics in peripheral nerve blocks has been used in only a few studies. AIM: Weaimed to evaluate the quality and duration of postoperativeanalgesia by addition of buprenorphine to 0.5% ropivacaine. Method: This random, prospective, double-blind study was carriedout on 68 patients, divided into two groups of each group having 34 patients. Group B: 30 ml 0.5% Ropivacaine + 0.3 mg 1 ml Buprenorphine, and Group C:30 ml 0.5% Ropivacaine + 1 ml normal saline,PNS guided supraclavicular brachial plexus block. Parameters observed were, onset time of sensory and motor block, duration of sensory and motor block, duration of post operative analgesia and any untowards side effects. Result: All demographic parameters age, sex, weight and height were statistically nonsignificant. On statistical analysis, the difference in the time to onset of sensory block and motor block, between Group B and Group C was found to be highly significant p value = <0.0001.Mean duration of sensory blocked in Group B was (mean ± SD) 612 ± 85.219 and group C was (mean ± standard deviation) 451.18± 70.356 minutes respectively. mean duration of motor blocked in Group B was (Mean ± SD) 540 ± 83.5 and group C was 379.0± 42.3 minutes respectively. The Duration of analgesia was longer in Group B than in Group C. Time for Rescue Analgesia was longer in Group B than in Group C. Conclusion: Buprenorphine added to local anaesthetic solution in supraclavicular brachial plexus block in dose of 3 μg/kg provides excellent postoperative analgesia lasting almost 2.5 times longer than local anaesthetic solution alone.