Background: The supraclavicular approach to brachial plexus block is the most common peripheral nerve block technique used for upper limb surgeries. Aim of the present study was to evaluate and compare the efficacy of clonidine and dexmedetomidine as an adjuvant to 0.25% bupivacaine in peripheral nerve stimulator guided supraclavicular brachial plexus block in upper limb surgery. Method: Total 80 patients of ASA grade I and II, age between 25-55 years were enrolled in the study and divided into two groups of 40 each. Group C received 39ml bupivacaine 0.25% (2.5mg/ml) + 1ml clonidine (1µg/ml) and group D received 39ml bupivacaine 0.25% (2.5mg/ml) + 1ml dexmedetomidine (1µg/ml). Parameters were observed include hemodynamic stability, onset time and duration of sensory and motor blockade, duration of analgesia and complications.