Background: Postoperative pain increases risk in patients with hypertension, coronary artery disease. Various adjuvants has been used to prolong the duration sensory block.Methods: This double blinded, randomized, controlled comparative study included 60 patients of either sex, ASA-I&II, 18-55 year age undergoing elective upper limb surgery who were randomly allocated into two groups (40 each): Group R-0.75% isobaric Ropivacaine 19 ml plus Normal Saline (1ml) and Group RC- 0.75% isobaric Ropivacaine 19 ml plus clonidine 150µg (1ml). Supraclavicular brachial plexus block was given by landmark technique. Onset and duration of sensory and motor blockade were recorded. P-value <0.05 considered statistically significant. Results: The mean time for onset of sensory block in group RC and R were 5.30 1.02 min and 10.83 1.05 min, respectively. The mean time for onset of motor block in group R was 13.87 1.33 min versus 7.87 1.33 min in group RC (p< 0.001). The mean duration of sensory block in group RC was significantly longer (11.42 0.6 hours) when compared to group R (8.01 0.64 hours).The mean duration of motor block in group RC was 10.10 0.68 hours versus 6.690.65 hours group R (p < 0.001). No significant adverse effect occurred in any group. Conclusions: we concluded that, the addition of Clonidine to Ropivacaine (0.75%) in supraclavicular block significantly fastens onset of sensory and motor block along with significant longer duration of sensory and motor block without any significant adverse effects.