Background: Effective management of postoperative pain following lower abdominal surgeries remains a key component of perioperative care. Spinal anesthesia with bupivacaine provides satisfactory surgical anesthesia but limited postoperative analgesia. The search for optimal adjuvants to prolong analgesia with minimal side effects has led to evaluation of dexmedetomidine and buprenorphine. Aim: To compare the onset and duration of sensory and motor block, duration of postoperative analgesia, and hemodynamic stability between intrathecal bupivacaine with dexmedetomidine and bupivacaine with buprenorphine in patients undergoing lower abdominal surgeries. Methods: Sixty adult patients (ASA I–II, aged 20–60 years) scheduled for elective lower abdominal surgeries were randomly allocated into two groups (n=30 each). Group D received 15 mg of 0.5% hyperbaric bupivacaine with 5 µg dexmedetomidine, while Group B received 15 mg bupivacaine with 60 µg buprenorphine intrathecally. Hemodynamic parameters, onset and regression times, duration of analgesia, and side effects were recorded and statistically analyzed. Results: The mean duration of postoperative analgesia was significantly longer in Group D (12.5 ± 2.3 h) than Group B (9.0 ± 1.5 h; p<0.001). The onset times of sensory and motor block were comparable. Hemodynamic parameters remained stable in both groups, with mild sedation in Group D being beneficial. Adverse effects were minimal in both groups. Conclusion: Intrathecal dexmedetomidine (5 µg) as an adjuvant to bupivacaine provides longer postoperative analgesia than buprenorphine (60 µg) without significant hemodynamic compromise or adverse events.