BACKGROUND AND OBJECTIVE:Regional anesthesia of the extremities and of the trunk is a useful alternative to general anesthesia in many situations. Brachial plexus block has now evolved into valuable and safe alternative to general anesthesia for upper limb surgeries. MATERIALS AND METHODS:This randomized study on Sixty ASA I and II candidates, were randomly allocated to receive 1.5% lidocaine (29 ml) with adrenaline (1:200,000) and either 1 ml of normal saline (group A, n=30) or 1 ml of dexamethasone (4 mg) (group B,n=30).The duration of sensory and motor block,duration of analgesia and number of rescue analgesics in post-op 24 hours were analyzed. RESULTS:The duration of sensory and motor blockade and post op analgesia (in mins) (178.60 ±30.26 vs. 420.73±80.87and 150.70±32.32vs.306.93±70.24 and 396.13±109.42 vs 705.80±121.46) respectively,were significantly longer in the dexamethasone group (P=0.001). CONCLUSION:Addition of dexamethasone to lidocaine with adrenaline in supraclavicular brachial plexus block prolongs the duration of sensory and motor blockade,duration of analgesia and lessens no of rescue analgesia needed in 24 hrs.