Abstract Background and Objectives: The study was conducted to compare the differences in onset, duration of analgesia of intrathecal hyperbaric bupivacaine 0.5% (GroupI) versus intrathecal hyperbaric bupivacaine 0.5% with buprenorphine 3 mg/kg (GroupII) in spinal anesthesia for lower abdominal and lower extremity surgeries. The combination of bupivacaine and buprenorphine helps anesthesiologist to prolong duration of analgesia without significant side effects. Materials and Methods: The study was prospective, randomized and double blinded. It involved 100 patients (50 per group) of ASAI and II, aged 1860 years undergoing lower abdominal and lower extremity surgeries under spinal anesthesia. The time of onset of sensory and motor block, duration of sensory and motor block, hemodynamic stability, visual analogue scale and postoperative analgesia were assessed. Results: The onset of sensory and motor blockade was significantly faster in groupII compared to groupI . The twosegment regression of sensory level and time to complete sensory recovery were significantly longer in groupII. The duration of analgesia was significantly prolonged in group II compared to groupI, Patients treated with intrathecal buprenorphine had a better pain relief as judged by visual analogue scale postoperatively. Adverse effects were minimal and easily treatable. Conclusion: Addition of intrathecal buprenorphine 3 mg/kg to hyperbaric bupivacaine 0.5% in spinal anesthesia provides better quality of anesthesia with hemodynamic stability and prolonged duration of analgesia postoperatively without significant side effects.