Background : This study was undertaken to observe and compare primarily, postoperative analgesia with intrathecal ketamine–midazolam and intrathecal ketamine–dexmedetomidine using hyperbaric bupivacaine for spinal anaesthesia and secondarily the onset and duration of sensory and motor block, hemodynamic effect and level of sedation. Method and Material : Patients were randomly assigned to one of the three groups, using a “slips of paper in a box” technique consisting 30 patients in each group. Group C (Control)– Patients receiving intrathecal spinal anaesthesia with 0.5% hyperbaric bupivacaine (3ml) + normal saline (0.5%). Group M– Patients receiving intrathecal spinal anaesthesia with 0.5% hyperbaric bupivacaine (3ml) + 5mg ketamine (preservative free) (0.1ml)+ 1 mg midazolam (preservative free)(0.2 ml). Group D – Patients receiving intrathecal spinal anaesthesia with 0.5% hyperbaric bupivacaine (3ml) + 5 mg ketamine (preservative free)(0.1ml) + 5µg dexmedetomidine(0.05ml) similar volumes were taken with insulin syringe and total solution was made 3.5ml by adding normal saline. Result : Onset of sensory and motor block was faster with both intrathecal ketamine–midazolam and ketamine–dexmedetomidine in comparison to control group but fastest onset was seen with intrathecal ketamine–dexmedetomidine. Maximum prolongation of duration of sensory block and motor block was seen with intrathecal bupivacaine with ketamine–dexmedetomidine. Total number of rescue analgesic required in 24 hours postoperatively was less with both the drug combinations but least with intrathecal ketamine–dexmedetomidine (Group D). Conclusion :Intrathecal dexmedetomidine with ketamine caused prolongation of postoperative analgesia and reduced requirement of rescue analgesic in postoperative period.