Aim of study: To compare efficacy of Clonidine and Dexmedetomidine as an adjuvant to local an aesthetic agent in supraclavicular brachial plexus block with respect to onset and duration of sensory and motor block, potency and duration of analgesia. Methodology: Total of 100 patients were studied Patients of either sex was randomly allocated into Group C and Group D. Group C –. Received Bupivacaine 0.25% (35 ml) + inj Clonidine 1 mcg / kg. Group D--. received Bupivacaine 0.25% (35 ml) + injDexmedetomidine 1 mcg/kg Sensory block was assessed by the pin prick method. Assessment of motor block was carried out each minute till complete motor blockade after the drug injection. Patients were assessed for duration of analgesia as per a numeric rating scale of 0 to 10. Results: The mean time for onset of sensory block in group D was 9.17±1.26 mins and that observed in group C was 11.07±2.14 mins. Mean duration of sensory block in group D was 690 ± 87.41min and in group C was 470 ± 55 min. The mean time for onset of motor block in group D was 12.63 ± 2.18 min and 15.17±1.77 min in group C. The mean duration of motor block in D group was 353.17 ± 41.24min and in group C was 270.51 ± 51.61min. The duration of analgesia was 448.40 ± 91.97 min in D group and 309.20±37.30 min in C group. Both Dexmedetomidine and Clonidine when used in the mentioned doses above does not produce haemodynamic instability and respiratory depression. Conclusion: From our study, the use of α-2 agonists, Dexmedetomidine (1 mcg/kg) and Clonidine (1 mcg/kg) as adjuvants to local anaesthetic solution (0.25% Bupivacaine ) in supraclavicular brachial plexus block for upper limb surgeries, we conclude that faster onset of sensory and motor block is seen with Dexmedetomidine as compared to Clonidine. Duration of sensory and motor block and postoperative analgesia is significantly prolonged with Dexmedetomidine as compared to Clonidine. Haemodynamic parameters, side effects and sedation scores are comparable between the two groups.