BACKGROUNDEpidural anaesthesia is one of the preferred modes of regional anaesthesia for lower limb surgeries, provides not only perioperative surgical anaesthesia but also post-operative analgesia for lower limb orthopaedic surgeries. Epidural anaesthesia reduces physiological stress related to surgery and improves surgical outcomes and gives good post-operative pain relief. Adequate post-operative pain relief is an integral part of anaesthesia, which is helpful in early ambulation of the patient as well as hospital discharge.This study was done to evaluate and compare the efficacy, analgesic effects, post-operative analgesia of epidurally administered dexmedetomidine or fentanyl along with ropivacaine for patients undergoing lower limb orthopaedic surgeries. MATERIALS AND METHODSA prospective, randomised, double-blinded study years was conducted at Chengalpattu Medical College, 60 patients of both gender aged 18 -60 undergoing elective lower limb orthopaedic surgeries were selected and randomly allotted into two groups. RESULTSGroup A and B were comparable with regard to their age, weight and sex. There is no statistically significant difference seen among two groups in the demographic profile. The mean time for onset of sensory block is 3.87 ± 0.681 (minutes) in Group A and 6.03 ± 1.47 (minutes) in Group B. There was significant difference among two groups in the time for onset of sensory block at T10 level, (p < 0.05). The mean time for complete motor block was 19 ± 3.151 (minutes) in Group A and 23.37 ± 2.58 (minutes) in Group B. There was significant difference among two groups in time for complete motor block, (p < 0.05). There was significant difference among two groups in sedation score, (p < 0.05). The mean time for first rescue analgesia was 373.67 ± 45.636 (minutes) in Group A and 314.1 ± 28.403 (minutes) in Group B. There was significant difference among two groups in time for first rescue analgesia, (p < 0.05). Patient in Group A had bradycardia, hypotension, dry mouth and Group B had nausea, vomiting and hypotension as main side effects. Group B patients also had shivering and pruritus as adverse effects. None of the patients had respiratory depression in both groups. CONCLUSIONDexmedetomidine seems to be a better adjuvant to epidural ropivacaine for lower limb orthopaedic surgeries. KEYWORDS BACKGROUNDEpidural anaesthesia is one of the preferred modes of regional anaesthesia for lower limb surgeries, provides not only peri-operative surgical anaesthesia but also postoperative analgesia (1,2) for lower limb orthopaedic surgeries. Epidural anaesthesia reduces physiological stress related to surgery and improves surgical outcomes, gives good postoperative pain relief. 3 Adequate post-operative pain relief is an integral part of anaesthesia, which is helpful in early ambulation of the patient as well as hospital discharge. The