BACKGROUND Various adjuvant used along with Local Anaesthetics [LA] to increase post-operative analgesia. Dexmedetomidine is a new highly selective α2 adrenergic agonist adjuvant. The objective of our study is to compare the duration of post-operative analgesia and sedation effect of dexmedetomidine-ropivacaine mixture with ropivacaine alone. Settings and Design-Tertiary level, teaching hospital. Prospective randomised double-blind study case control study. MATERIALS AND METHODS 50 patients aged between 20 to 60 years of age of ASA Grade 1 and 2 undergoing elective spine surgeries were randomly allocated into two groups of 25 patients each. Patients in Group D receives dexmedetomidine 50 µg + 0.25% ropivacaine 14 mL total of 15 mL as bolus and followed by dexmedetomidine + 0.25% ropivacaine mixture infusion at 5 mL/hr. (100 µg of (1 mL) dexmedetomidine in 49 mL 0.25% Ropivacaine) as continuous infusion through an 18-G epidural catheter. Group R receives 0.25% ropivacaine 14 mL + 1 mL of normal saline total of 125 mL as bolus and followed by 0.25% ropivacaine 5 mL/hr. as continuous infusion through an epidural catheter in the post-operative period for the first 24 hrs. Time of bolus dose is taken as zero. Infusion was discontinued after 24 hrs. and catheter removed and dressing done. Besides cardiorespiratory parameters and sedation scores, Visual Analogue Score (VAS), Time of Rescue Analgesia and Total Amount of Rescue Analgesia was compared in each group. At the end of study, data was compiled systematically and analysed using ANOVA with post-hoc significance, Chi-square test and Fisher's exact test. Value of P < 0.05 is considered significant and P < 0.001 as highly significant. RESULTS Significantly onset of action is rapid in Group 1 patients, where dexmedetomidine-ropivacaine mixture is used as compared to control group. Average time of onset of action in Group 1 is 8.16 ± 2.5 mins. compared to 13.6 ± 4.1 in Group 2. A higher number of patients in control group has requested for rescue analgesia in the post-operative period than Group 1 patients. Average time for first request of rescue analgesia in Group 1 patients is 312.2 ± 16.1 mins. compared to 156.2 ± 12.6 mins. in control group. Sedation effect was found to be better in Group 1 patients as compared to control group. CONCLUSION It was concluded that dexmedetomidine used as an adjuvant to ropivacaine in surgical wound infiltration for post-operative analgesia in patients undergoing spine surgeries provides longer duration of post-operative pain relief compared to ropivacaine alone.