INTRODUCTION: Brachial plexus block is a reliable regional anaesthetic technique for upper limb surgery. Adjuvants to local anesthetics for brachial plexus block may enhance the quality and duration of sensory, motor blockade and analgesia. We used dexamethasone 8 mg along with 0.5% ropivacaine for supraclavicular brachial plexus block. Aims & Objectives : 1.To evaluate the onset and duration of sensory and motor blockade. 2. To study the duration of postoperative analgesia. Methods and materials: 60 ASA grade I and II patients, 21–60 years old, scheduled for upper limb surgeries under supraclavicular brachial plexus block, were included in this prospective study. The patients were randomly assigned to two groups, Group R which received inj.ropivacaine 0.5% 30ml + 2ml normal saline and Group RD which received inj.ropivacaine 0.5% 30 ml+ inj dexamethasone 2 ml (8 mg). Onset and recovery time of sensory and motor block, quality of block and duration of analgesia were studied in both groups. Results: The two groups were comparable in demographic data. Group RD showed early onset of sensory and motor block (P<0.05). Duration of sensory and motor block was also prolonged in group RD (P<0.05) .Mean time for analgesia requirement in postoperative period was significant longer in group B.(P<0.05). Conclusion: Brachial plexus block via supraclavicular approach provide postoperative analgesia of short duration even when a long acting local anesthetic is used without adjuvant . Adjuvant like dexamethasone 8mg to 0.5% ropivacaine for supraclavicular brachial plexus block provides faster onset and prolonged duration of sensory and motor blockade