Introduction: Pain in the postoperative period produces many physiological and psychological effects. Opioids when combined with local anesthetics for epidural analgesia provide effective pain relief by acting on spinal opiate receptors. They enhance the effect of pain relief and prolong the duration of analgesia. 

Aims and objectives: To compare the effects of Buprenorphine and Butorphanol when added to Bupivacaine for postoperative epidural analgesia with regards to onset and duration of analgesia, hemodynamic variables and sedation scores. 

Materials and Methods: This prospective randomized and double blind observational study was conducted in 100 ASA I and II patients scheduled for lower limb orthopedic surgeries and were randomized into two groups A and B. group A Patients received 8ml of 0.125% Bupivacaine+ 2mcg/ kg of buprenorphine Whereas group B received 8ml of 0.125% of Bupivacaine + 3mcg/kg of butorphanol. Onset and duration of analgesia, sedation, hemodynamic variables and side effects were recorded and compared between the two groups. 

Results: The mean onset of analgesia in groupA was 5.28 min compared to Group-B which was 8.8 min which is statistically significant (p<0.05). Duration of analgesia in
Group-A was 491.7 min compared to Group- B, which was 338.7min and statistically significant (P<0.05). Conclusion: We conclude that Buprenorphine added to Bupivacaine provides early onset and prolonged postoperative epidural analgesia compared to epidural butorphanol.