Background: Subarachnoid block (SAB) is a widely used technique for anaesthesia in lower abdominal and lower limb surgeries. This comparative study evaluates the efficacy and safety of bupivacaine with midazolam versus bupivacaine with fentanyl in adult patients undergoing lower abdominal surgeries. Objectives: To evaluate the onset time of sensory and motor block with each drug combination and to compare the duration of sensory and motor block provided by Bupivacaine with Midazolam versus Bupivacaine with Fentanyl. Methods: A randomized controlled trial was conducted with two groups receiving one of the two drug combinations. Primary outcomes included pain scores, onset, and duration of sensory and motor block, while secondary outcomes encompassed hemodynamic stability, adverse effects, and patient satisfaction. Results: Results revealed no significant differences between the two groups across primary and secondary outcomes, indicating comparable efficacy and safety profiles. These findings provide valuable insights into optimizing anaesthesia management in this patient population. Conclusion: The comparative study evaluating bupivacaine with midazolam versus bupivacaine with fentanyl as adjuvants in SAB procedures for lower abdominal and lower limb surgeries elucidated compelling insights into anaesthesia management practices. Both adjuvant combinations demonstrated comparable efficacy, safety, and patient satisfaction, highlighting the equipoise between midazolam and fentanyl as adjuncts to bupivacaine in achieving optimal anaesthesia outcomes