Background Adjuvants are added to improve the quality, to accelerate the onset of action and to overcome the problems of spinal anaesthesia. Depending on the purpose various adjuvants like morphine, fentanyl, clonidine, midazolam and dexmedetomidine are added. Adjuvants are administered by various routes like epidural, intrathecal and intravenous. Materials and methods Following detailed pre-anesthetic check-up, patients were randomised into 2 groups in a sealed envelope, Group D received 2.5ml of 0.5% hyperbaric bupivacaine with 5µg dexmedetomidine and Group F received 2.5ml of 0.5% hyperbaric bupivacaine with 25µg fentanyl. Subarachnoid block was given between L3-L4 space with 25G Quincke spinal needle under aseptic precautions after free and clear flow of CSF in sitting posture. Onset of action, level of blockade, sedation score, duration of analgesia, adverse effects and hemodynamics were monitored. The first rescue analgesia was given when Visual Analogue Scale (VAS) was >4. Results In our study dexmedetomidine provided better sensory block, motor block and longer duration of analgesia. The highest sensory level achievedby group D 6(4 – 8) and in group F was 8(6-10)(p 0.05). Conclusion We conclude that dexmedetomidine may be used as an alternate to fentanyl for intrathecal use and it may find a place forregular use in clinical practice.