Background: Supraclavicular brachial plexus block is a widely used regional anesthesia technique for upper limb surgeries, offering effective pain relief. Dexmedetomidine has shown promise as an adjuvant to local anesthetics, potentially enhancing block characteristics and prolonging postoperative analgesia. Aim and Objective: To compare the efficacy and safety of dexmedetomidine as an adjuvant to bupivacaine-lignocaine combination versus plain bupivacaine-lignocaine combination in supraclavicular brachial plexus block for patients undergoing forearm and hand surgeries. Materials and Methods: A prospective, randomized, double-blind, comparative trial was conducted at RKDF Medical College Hospital and Research Centre, Bhopal, India, from April 2023 to March 2024. Sixty patients were randomized into two groups: Group D (dexmedetomidine-adjuvanted bupivacaine-lignocaine) and Group C (plain bupivacaine-lignocaine). Primary outcome measures included onset time, sensory and motor blockade duration, and postoperative analgesic consumption. Secondary outcomes included hemodynamic parameters, sedation scores and adverse events. Results: The onset time of sensory block was significantly shorter in Group D compared to Group C (6.8 ± 1.2 minutes vs. 8.5 ± 1.4 minutes, p < 0.001). Similarly, the onset time of the motor block was shorter in Group D (9.3 ± 1.5 minutes) compared to Group C (11.1 ± 1.7 minutes, p < 0.001). The duration of sensory and motor blockade was significantly prolonged in Group D compared to Group C (12.4 ± 2.1 hours vs. 9.8 ± 1.8 hours, p < 0.001; 11.6 ± 2.0 hours vs. 9.1 ± 1.6 hours, p < 0.001, respectively). Postoperative analgesic consumption was lower in Group D compared to Group C (35.2 ± 8.3 mg vs. 48.9 ± 10.6 mg of intravenous tramadol, p < 0.001). Conclusion: Dexmedetomidine as an adjuvant to bupivacaine-lignocaine combination in supraclavicular brachial plexus block significantly improves block characteristics and postoperative analgesia without increasing adverse events. Integration of dexmedetomidine into perioperative pain management protocols may enhance outcomes in upper limb surgeries.