Introduction: Commonly we use 0.5% hyperbaric bupivacaine in spinal anaesthesia. Adjuvants to spinal anaesthesia have been used to improve quality of analgesia and in prolongation of anaesthetic duration. Dexmedetomidine has been studied and shown to have synergism with bupivacaine and other local anesthetics. Recently, in a few studies, intravenous (IV) dexmedetomidine has been shown to improve analgesic quality. In this study we aimed at finding the efficacy of (IV) dexmedetomidine in improving the analgesia quality and duration of subarachnoid blockade in our hospital scenario. Materials and Methods: Ninety patients were divided into two groups of 45 each. In Group A - 3.5 mL of 0.5% hyperbaric bupivacaine was used for spinal anesthesia. In Group B - 3.5 mL 0.5% hyperbaric bupivacaine used for spinal anaesthesia, thirty minutes later a loading dose of IV dexmedetomidine 1 mcg/Kg was infused over 30 min followed by maintenance dose of 0.3 mcg/kg/hr IV dexmedetomidine infused till the end of surgery. In Group A, isotonic saline was used instead of dexmedetomidine preparation. Duration of motor block, sensory block, analgesia, hemodynamic changes, sedation levels, complications and side effects were noted and compared between the study groups in patients undergoing lower abdominal surgeries. Results: The duration of motor block in Group A was 149.38 ± 21.32 minutes vs.189.13 ± 31.18 minutes in Group B (p< 0.05), duration of sensory block in Group A was 166.79 ± 33.12 minutes vs. 248.13 ± 48.32 minutes in Group B (p< 0.05), and duration of analgesia in Group A was 198.69 ± 41.38 minutes vs. 298.57 ± 34.65 minutes in Group B (p< 0.05). Conclusion: Use of IV dexmedetomidine improves analgesia quality and prolongs anaesthesia duration in subarachnoid block with 0.5% hyperbaric bupivacaine without any hemodynamic instability and with optimum sedation.