Introduction: Peripheral nerve blocks have become important in clinical practice because of their role in post-operative pain relief, shortening of patient recovery time & avoiding risks and adverse effects of general anaesthesia. Bupivacaine is a long acting local anaesthetic. Due to its long duration of action and combined with its high quality sensory blockade compared to motor blockade it has been the most commonly used local anaesthetic for peripheral nerve blocks. Ropivacaine is a newer, long acting local anaesthetic whose neuronal blocking potential used in peripheral nerve blockade seems to be equal or superior to bupivacaine. Method of collection of data: Sixty patients aged between 18 years and 60 years, of physical status ASA grade 2 and ASA grade 3 undergoing elective upper limb surgeries lasting more than 30 minutes were included in the study after getting ethical clearance. Each patient was randomly allocated to one of the two groups of 30 patients each. The patients were explained about the procedure and premedicated with tab alprazolam 0.5mg, and tab ranitidine 150 mg. The anesthetic technique employed was supraclavicular brachial plexus block using 30 ml of either 0.5% bupivacaine or 0.5% ropivacaine. Results: In our study, we observed that onset time of sensory block was earlier in bupivacaine group in comparison with ropivacaine group. Onset time of motor block was earlier in bupivacaine group in comparison with ropivacaine group having a mean value of 22.90±1.88 minutes which is statistically significant. Duration of sensory block was 362.00±47.66 minutes with bupivacaine group and 322.00±42.38 minutes with ropivacaine group. The duration of sensory block was longer in bupivaine group compared with ropivacaine group. The duration of motor block was 399.00±41.05 minutes with bupivacaine group and 366.00±37.29 minutes with ropivacaine group. The duration of motor block was longer in bupivaine group compared with ropivacaine group. The duration of analgesia was 402.00±42.86 minutes with bupivacaine group (Group B) and 371.00±36.52 minutes with ropivacaine group (Group R) in our study. Conclusion: On the basis of our study, we can draw the conclusion that at equal volumes bupivacaine 0.5% has an advantage over ropivacaine 0.5% for supraclavicular brachial plexus block in terms of early onset of sensory blockade, early onset of motor blockade, prolonged duration of sensory blockade, prolonged duration of motor blockade, prolonged duration of analgesia.