Background and aim: Supraclavicular brachial plexus block under USG guidance is a safer and better alternative to blind blocks or general anesthesia for upper extremity surgeries and also provides good postoperative pain relief. This study aimed to compare theanesthetic effect of dexmedetomidine as an adjuvant to 0.5% ropivacaine in supraclavicular brachial plexus block for upper extremity surgery. Method: This Randomised double blind controlled interventional study includes sixty ASA physical status I and II patients of either sex for elective upper limb surgery under USG guided supraclavicular brachial plexus block divided into two groups of 30 each. Group A received 20ml of 0.5% ropivacaine+5ml of normal saline(total volume 25ml) and Group B received 20ml of 0.5%ropivcaine+50µg dexmedetomidine(0.5ml) +4.5ml normal saline(total volume 25ml).Study parameters were hemodynamic profile (HR ,SBP, DBP, MBP), SpO2, onset time and duration of motor and sensory blockade, time of 1st dose of rescue analgesia, duration of analgesia, and side effects. Result: Demographic profile of both groups were same but there is statistically significant difference in mean onset time and duration of motor and sensory blockade and analgesia duration.Conclusion: Dexmedetomidine when used as an adjuvant to ropivacaine in supraclavicular plexus block hastens the onset time and increases the duration of sensory and motor blockade along with it prolongs the duration postoperative analgesia.