Aim: To explore the impact of dexmedetomedine as adjuvant to hyperbaric bupivacaine 0.5% in spinal anaesthesia in caesarian section. Methods: This study was conducted in Services Hospital, Lahore from 23-2-21 to 31-05-21. Two groups of 30 each were made by dividing patients randomly. Group B was given hyperbaric bupivacaine 0.5% (10mg) diluted in normal saline and in Group BD dexmedetomedine 5µg (0.5 ml) was added to 10mg hyperbaric bupivacaine (0.5%). Spinal Anaesthesia was administered with 25G spinal needle. Haemodynamic changes, onset and duration of sensory and motor block were documented. Inadequate perioperative analgesia was relieved with ketamine. Comparison of hemodynamics was done by independent sample t-test. Characteristics of motor and sensory block, analgesic time period were all presented as median (IQR) and compared by Mann Whitney U test. Comparison of categorical variables was done by Chi square. p< 0.05 was considered significant. Results: The median time for sensory block onset was 2.0(2.0 - 3.0) in Group B vs 2.0(2.0 - 3.0) BD. The median time to reach maximum sensory block was not significantly different. (p-0.151). The two segment sensory regression time was significantly longer in group BD with median time 2.2(2.0 – 3.0) vs 1.5(1.3 – 2.0) hours in group B. Significant increase in analgesic duration was seen in group BD (p<0.001). Onset of motor block was higher in group BD significantly (p-0.04). Significant increase in motor block duration was seen (p<0.05) in BD vs B group with respective median times 6.0(5.5 – 7.0) and 3.5(3.0 – 4.0). Conclusion: Intrathecal Dexmedetomidine 5 µg with hyperbaric bupivacaine significantly prolongs both sensory and motor block and prolongs the duration of analgesia in lower segment caesarian section. Keywords: Dexmedetomedine, Spinal Anaesthesia, Sensory block, Motor block