Background: Good postoperative analgesia helps to reduce postoperative stress response, improve patient satisfaction, and improve outcome. Epidural block with local anaesthetic with or without additives is being used for perioperative analgesia. Various additives have been used to enhance the effect of regional blocks including epidural blocks. Objective: To assess the postoperative analgesia in patients single shot epidural dexamethasone to bupivacaine undergoing lower abdominal surgeries. Methods: This was a prospective, randomized, double blind study carried out at the Dept. of Anesthesia, Sheikh Russel National Gastroliver institute and hospital, Mohakhali, Dhaka, Bangladesh from July to December 2021. One hundred (100) adults patients of ASA physical status I and II of age Group 16-65 years and undergoing routine elective lower abdominal surgery. The patients were randomized into two groups. Group A received 9ml of 0.5% bupivacaine plain with 1 ml of normal saline. Group B received 9ml of 0.5% bupivacaine plain 9 ml with 1 ml of dexamethasone (4mg). After standard balanced anaesthesia technique, patients were observed in postoperative period for pain and hemodynamic variables accordingly. Results: In our study 100 patients belonging to ASA physical status I and II undergoing lower abdominal surgery under general anaesthesia were studied. The patient’s age ranged from 16 to 65 years. Our study showed significantly longer duration of analgesia of 8 hours when dexamethasone was added to bupivacaine for single shot epidural injection compared to four and half hours when bupivacaine alone was used (p<0.001). Consumption of rescue analgesic, Tramadol, was significantly lower in dexamethasone group in 24 hours (168.32±49.72 mg in Group A and 113.72±60.57mg in Group B, p<0.001). No adverse events were noted. The both groups the lowest blood pressure was observed at ½ hours following the block and highest at 6 hours. While comparing the two groups at 6 hours the blood pressure in Group B (120.56±12.06) was significantly less than that in Group A (125.90±9.54) (p=0.024). No significant difference was observed at ½ hours, 12 hours and 24 hours after the block. Conclusion: In conclusion, the quality of analgesia it offers not only in post-operative pain but also in labour analgesia and chronic pain management. Addition of dexamethasone to bupivacaine for single shot epidural block almost doubled the duration of analgesia. Single shot epidural block using bupivacaine with addition of dexamethasone provides effective post-operative analgesia and significantly reduced the postoperative rescue analgesic requirement.