Background: Brachial plexus block is a reliable, regional anesthetic technique for upper arm surgeries. Opioid agonist-antagonists are used as adjuvant to enhance the analgesia of bupivacaine. The present study was aimed to compare the analgesic efficacy and safety of nalbuphine and tramadol as an adjuvant to 0.5% bupivacaine for brachial plexus block. Materials and Methods: Thirty adult patients of ASA I and II of both genders were randomized into two Groups of fifteen patients, Group BT receive 28 ml of 0.5% bupivacaine with 2 ml of tramadol and Group BN receive 28 ml of 0.5% bupivacaine with 2 ml of nalbuphine 20 mg for supraclavicular brachial plexus block. Patients were observed for onset and duration of sensory and motor block with duration of pain relief as primary end points while occurrence of any adverse effect due to technique or nalbuphine was noted as secondary outcome. Results: In Group BN, there was a statistically significant shorter time to onset of sensory blockade (10.46 ± 1.5 min vs 13.66 ± 2.5 min, p < 0.001), shorter onset time to achieve motor block (14.4 ± 2.5 min vs. 18.46 ± 3.5 min, p < 0.001), longer duration of motor block (291.4 min vs 363.07 min, p < 0.001), and prolonged analgesia (456 min vs 409.13 min, p = 0.003). No significant side effects were seen in any of the groups. Conclusion: Addition of nalbuphine to 0.5% bupivacaine in supraclavicular brachial plexus block significantly hastens the onset, and prolongs the duration of sensorimotor blockade and analgesia when compared with tramadol as an additive. Both the drugs were comparable in terms of safety.