Background: Opioid like Buprenorphine has been widely used as adjuvant intrathecally for providing prolonged post operative pain relief. Their advantages of neuraxial narcotics over systemic narcotics are well established. IntrathecalMidazolam, abenzodiazepine derivative apart from its own analgesic and sedative effect, it potentiate the analgesic effect of Bupivacaine. This study was conducted to compare the efficacy of intrathecal Buprenorphine (150µg) with intrathecal Midazolam (2.5mg) when used as an adjuvant to 0.5% Bupivacaine for lower abdominal surgeries and also to observe any side effects. Methods: After approval from hospital ethical committee, 90 patients between the age group of 20­60 years was taken. Informed consent from the patient was taken. All patients from ASA I and ASA II were allotted in three groups of 30 patients each. Group B was given 3.5 ml of 0.5% bupivacaine (heavy) with 150µg (0.5ml) buprenorphine intrathecally. Group M was given 3.5 ml of 0.5% Bupivacaine (heavy) with 2.5 mg (0.5ml) midazolam (preservative free) intrathecally. Group C was given 3.5 ml of 0.5% bupivacaine (heavy) with (0.5 ml) of Normal Saline intrathecally as controlled group Statistical analysis was performed using ANOVA test and T­test. p value < 0.05 was considered significant. Result: Onset of sensory and motor is fastest in Midazolam group while Buprenorphine provided prolonged duration of analgesia post­operatively (827.17+67.77 min.) as compared to Midazolam (297.5+33.21min.). Conclusion: Addition of Buprenorphine provides prolonged post­operative analgesia compared to other groups but sensory & motor onset is fastest with Midazolam.