Brachial plexus block is a suitable alternative to GA. It is reliable, safe, effective, low-cost and most complete anaesthesia with good postoperative analgesia for upper limb surgery. Local anaesthetics alone for supraclavicular brachial plexus block provide good operative conditions but have shorter duration of postoperative analgesia. Numerous adjuncts have been added to enhance the efficacy of the block. The work was undertaken to compare the onset time and duration of analgesia between tramadol and dexamethasone when used as an adjuvant to bupivacaine in supraclavicular brachial plexus block. Total 60 patients underwent upper extremity surgery under brachial plexus block were randomly divided into two equal groups of 30 each; one group received tramadol (2mg/kg) and the other group received dexamethasone (0.2mg/kg) as an adjuvant to bupivacaine. The onset of action and duration of analgesia in the two groups were compared. Dexamethasone when added to bupivacaine in brachial plexus block it results significantly early onset and markedly prolonged duration of post-operative analgesia, which was significantly higher in comparison with tramadol.