Background and Aims:Various opioid additives have been trialed to prolong brachial plexus block. We evaluated the effect of adding nalbuphine hydrochloride to levobupivacaine for supraclavicular brachial plexus blockade. The primary end-points were the onset and duration of sensory and motor blocks and duration of analgesia.Materials and Methods:Seventy-eight patients (aged 25–45 years) posted for ambulatory forearm and hand surgery under supraclavicular brachial plexus block were divided into two equal groups (Groups LN and LC) in a randomized, double-blind fashion. In Group LN (n = 39), 30 ml 0.5% levobupivacaine + 10 mg (diluted in 2 ml 0.9% saline) nalbuphine hydrochloride, and in Group LC (n = 39), 30 ml 0.5% levobupivacaine + 2 ml normal saline (0.9%) were administered in supraclavicular block. Sensory and motor block onset times and block durations, time to first analgesic use, total analgesic need, postoperative visual analog scale (VAS), hemodynamics, and side effects were recorded for each patient.Results:Although with similar demographic profile and block (sensory and motor) onset time, sensory and motor block duration and time to first analgesic use were significantly longer and the total need for rescue analgesics was lower in Group LN (P < 0.05) than Group LC. Postoperative VAS value at 24 h was significantly lower in Group LN (P < 0.05). Intraoperative hemodynamics was comparable between two groups, and no any appreciable side effect was noted throughout the study period.Conclusion:It can be concluded that adding nalbuphine hydrochloride to supraclavicular brachial plexus block increases the sensory and motor block duration and time to first analgesic use, and decreases total analgesic use with no side effects.