Background: Postoperative pain relief is a growing concern for an anesthesiologist as an uneventful postoperative period makes surgery a comfortable proposition for surgical patients. Objectives: To assess the duration of effective analgesia. To assess hemodynamic parameters during the surgery and to determine any adverse effects if any. Methods: A prospective randomized controlled trial was done in patients posted for elective lower abdominal and lower limb surgeries for 2 years. Two groups were decided Group M (n=35), received 3 ml of 0.5% hyperbaric bupivacaine, preservative free magnesium sulfate 50%, 0.1 ml (50 mg) and preservative free normal saline 0.5 ml. Group CM (n=35), received 3 ml of 0.5% hyperbaric bupivacaine, preservative free magnesium sulfate 50%, 0.1 ml (50 mg) and clonidine 0.5 ml (75 μg). SPSS (version 22.0) was used for analysis. Results: Most of the patients belonged to age group between 41–50 years in both the groups. The duration (minutes) of analgesia was prolonged in Group CM compared to group M. By using unpaired t-tests, p-value was < 0.0001. The total dose of diclofenac given was less in Group CM compared to Group M. Pulse rate and Mean arterial pressure were not significant. No significant difference with respect to hypotension and bradycardia (p-value > 0.05). Conclusion: The duration of postoperative analgesia seems to be augmented by the combination since these are more prolonged than what is expected with either of the drugs used alone as adjuvants.