Background: Spinal anaesthesia is most common technique for patients undergoing abdominal hysterectomy owing to its attributes: rapid onset, adequate motor blockade, easier to administer and cost effectiveness. Dexmedetomidine have been evaluated as neuraxial adjuvant, sedative and also for postoperative pain adjunct. Objectives: To evaluate effect of intravenous dexmedetomidine (0.25mcg/kg) bolus dose for prolonging duration of spinal anaesthesia in patients undergoing elective abdominal hysterectomy. Materials & Methods: This prospective, double-blind, randomized study was conducted in adult patients scheduled to undergo abdominal hysterectomy. After 15 minutes of subarachnoid block, they were divided into two equal groups and given either 0.25mcg/kg of intravenous dexmedetomidine (group D) or intravenous normal saline (group C). Sensory block and motor block characteristics along with time for first rescue analgesia requirement postoperatively were recorded. Duration of postoperative analgesia was noted from the time of subarachnoid block to the first demand of rescue analgesia. Results: There was no significant difference in onset of sensory block in both groups (p>0.05) but there was statistically significant difference for time for reach maximum highest sensory block (T6) between both the groups (p<0.05). Time to get grade 0 from grade 3 blocks was statistically significant in both groups (p<0.01). Time from sensory onset time to first dose of rescue analgesic were significantly prolonged in group D as compared to group C (p<0.01). Conclusions: This study concluded that intravenous dexmedetomidine 0.25μg/kg was significantly better in terms of sensory, motor block characteristics and postoperative analgesic requirement as compared to placebo.