Background: Brachial plexus block is the commonest form of regional anaesthesia being used for upper limb surgeries Bupivacaine and Ropivacaine have been extensively studied & their properties with respect to onset, duration and quality of block.Aim: The aim of this study was to compare of onset, duration of sensory-motor block and any adverse effects between 0.5% Bupivacaine and 0.5% Ropivacaine in brachial plexus block Materials & Methods:A total of 80 patients were enrolled and randomized into two groups. Group I with 40 patients was given 30mL of 0.5% bupivacaine and Group II with 40 patients were given 30 mL of 0.5%, Ropivacaine drugs were used for giving supraclavicular brachial plexus block. Parameters assessed were onset and duration of sensory and motor block, duration of analgesia, and any adverse events other parameters were assessed. Results: The onset of blockade, both & motor was earlier in Bupivacaine as compared to Ropivacaine group. Mean duration of blockade, both sensory & motor and duration of post-operative analgesia was more in the Bupivacaine group. Adverse events and hemodynamic status was same in both the groups. Conclusions: Ropivacaine was less effective than bupivacaine, regarding onset of blockade, duration of blockade and postoperatively duration of analgesia No significant adverse effects were noted in these two groups.