Background: Supraclavicular Brachial plexus block provides safe, effective, low-cost anaesthesia with excellent post-operative analgesia. With the advent of ultrasound guidance establishing the blockade has been easier with reduced drug dosage and less complications. Objective: To compare the effect of bupivacaine 0.5% & ropivacaine 0.5% used for ultrasound guided supraclavicular brachial plexus block with respect to onset and duration of sensory blockade, onset and duration of motor blockade, duration of analgesia. Methods: 60 patients of ASA class 1 and 2 for upper limb surgical procedures were randomly allocated into two groups of 30 each, Group B-i.e. Bupivacaine group receives 20 ml Bupivacaine 0.5% (5 mg/ml), Group R-i.e. Ropivacaine group receives 20 ml Ropivacaine 0.5% (5mg/ml). With ultrasound guidance supraclavicular brachial plexus block was administered. Testing for onset of sensory blockade was done using pin prick method, motor block was assessed using modified bromage scale, post operatively patients would be assessed for the duration of sensory and motor blockade. Results: The present study shows that the onset of sensory, motor blocks was significantly earlier in bupivacaine 0.5% group (Group B) in comparision with ropivacaine 0.5% group (Group R). The duration of motor, sensory block and duration of analgesia was longer in Bupivacaine 0.5% group compared with Ropivacaine 0.5% group. Conclusion: Bupivacaine 0.5% has early onset of sensory blockade, early onset of motor blockade, prolonged duration of sensory blockade, motor blockade, prolonged duration of analgesia when compared to ropivacaine 0.5% at equal volumes when used for supraclavicular brachial plexus block under ultrasound guidance without any adverse effects.