Popliteal nerve block is a useful technique for ankle and foot surgeries, particularly in patients thought unsuitable for central neuraxial block. Agents such as magnesium and clonidine are used as adjuvants to local anaesthetics in peripheral nerve blockade. The present study is taken up to compare the clinical efficacy of 20 ml of 0.5% bupivacaine with 2 ml of 10% magnesium sulphate and 20 ml of 0.5% bupivacaine with 2 ml of 7.5% sodium bicarbonate for popliteal nerve block. Material and Methods: Present study was hospital based prospective, randomised clinical study, conducted in patients Aged between 18-70 years, ASA physical status I, II and III of either sex, posted for elective ankle and foot surgeries. 60 patients were randomly divided into 2 groups as Group M (Magnesium Sulphate) & group S (Sodium Bicarbonate). Results: There were no statistically significant differences between these groups in demographics, ASA grading and the type of surgeries. The time of onset of sensory level block in Group S was 12.73±1.33(in mins) and in Group M was 16.83±1.66(in mins), difference was statistically significant. The duration of sensory level block in Group S was 13.48±1.29(in hours) and in Group M was 17.96±1.95(in hours), difference was statistically significant. The time of onset of motor block in Group S was 16.13±1.59 (in mins) and in Group M was 24.37±1.40(in mins) , difference was statistically significant. The duration of motor level block in Group S was 7.43±0.88(in hours) and in Group M was 10.35±0.81(in hours), difference was statistically significant. Conclusion: Both magnesium sulphate and sodium bicarbonate do not cause any hemodynamic instability, adverse effects or complications and provide excellent intra operative anaesthesia with post operative analgesia