Background: Brachial plexus block is widely employed regional nerve block technique for upper extremity surgeries. Supraclavicular approach is most preferred as it is easy and gives consistency in results with minimal side effects. Various adjuvants have been added to local anesthetics to Prolong the duration of anesthesia. In our study, Dexamethasone has been added to ropivacaine to evaluate its effect on duration of analgesia. Aim: Evaluating the effect of adding dexamethasone to ropivacaine in supraclavicular brachial plexus block compared with ropivacaine alone. Materials and Methods: A Randomised prospective and double blinded clinical study. Seventy patients of ASA I and II of either sex, aged 20-65 years, undergoing various elective upper limb surgeries were equally divided into two groups and given supraclavicular brachial plexus block. Group A patients (n = 35) received 30 ml of 0.5% ropivacaine with distilled water (2 ml)control group whereas Group B patients (n = 35) received 30 ml of 0.5% ropivacaine with 8 mg dexamethasone (2 ml) made study group. The primary outcome measures were the onset of sensory and motor block, duration of analgesia and pain scores. Results: The onset of sensory and motor block was seen to be faster in Group B than Group A. Patients in group A required first rescue analgesia earlier (410.28± 38.70 min) thanthose of Group Bpatients (996.60 ± 56.60 min), which was found statistically significant (P < 0.002). The total dose of rescue analgesia was higher in Group A as compared to Group B, which was statistically significant (P < 0.00). Conclusion: Addition of dexamethasone (8 mg) to ropivacaine in supraclavicular brachial plexus approach significantly and safely prolongs sensory, motor blockade and postoperative analgesia more than that produced by ropivacaine alone.