Introduction: Regional anesthesia is particularly indicated for patients undergoing peripheral limb surgery because it provides effective intraoperative anesthesia and postoperative pain control. Supraclavicular approach of brachial plexus block is the most commonly used approach and provides the most complete and reliable anesthesia for upper limb surgery. The concurrent injection of α2 adrenergic agonist drugs has been suggested to improve the nerve block characteristic of LA solutions. Objectives: To assess the time of onset and duration of action of Ropivacaine with MgSO4 and Ropivacaine with dexmeditomidine. Materials and Methods: Patients with American Society of Anesthesiologists physical status (ASA) Grade 1 or 2 posted for  elective upper limb orthopedic surgeries were included in the study. The study patients were randomly divided into 2 Groups with 25 patients in each group namely Group A (n = 25): 20 ml 0.75% ropivacaine (150 mg) +2.5 ml (250 mg) MgSO4 and Group B (n = 25): 20 ml 0.75% ropivacaine (150 mg) + 2.5 ml dexmedetomidine (1 mcg/kg + normal saline). Brachial plexus block through supraclavicular approach was performed. The primary outcome measure was the onset of sensory and motor blockade, while secondary was the duration of sensory and motor blockade. The adverse reactions during the perioperative period were recorded. Results: Overall, the onset of motor and sensory blockade in Group B was faster than Group A and the duration of motor and sensory blockade in Group B was longer than Group A, which was statistically significant with p - value < 0.001. Conclusion: Dexmedetomidine as an adjuvant to Ropivacaine in the supraclavicular brachial plexus block for upper limb surgery significantly shortens the onset time for sensory and motor block and prolongs the duration of sensory and motor blocks with the use of ultrasound guidance for the peripheral nerve blocks.