Introduction: The incidence of femoral neck fractures, one of the most common traumatic injuries in elderly patients increases continuously among the ageing population. Anaesthetic management of NOF is either spinal or general anaesthesia. One of the modalities for postoperative pain control is lower limb peripheral nerve blocks. Opioids like fentanyl, tramadol, midazolam, neostigmine, clonidine and dexmedetomidine are being used. Dexmedetomidine has been used as an adjuvant in local anaesthetic solutions at a dose of 1 µg/kg in lumbar plexus block and has convincingly shown to prolong the duration of anaesthesia and post-operative analgesia. Despite these assumptions, an understanding of the mechanism and site of the action of dexmedetomidine used as an adjuvant to lumbar plexus block is unknown. Hence, this study was conducted with Aim of: (1) The effectivity of dexmedetomedine as an adjuvant to Ropivacaine 0.75% in lumbar plexus block. (2) To study the adverse effects of dexmedetomidine in lumbar plexus block. Methods: This is a prospective, double blind randomised systemic control trial. It comprises of three groups. Lumbar plexus block was given using Inmed (R) nerve stimulator using a 100-mm-long stimulating needle. Capdevila is the current technique of choice. Results: The mean age and sex in Group A (d) (Study Group), Group B (ivd) (Control Group) and Group C (r) (Placebo Group) are similar. Surgery lasted for 40 to 60 minutes. All three groups were statistically comparable. Mean duration of sensory block was 586 ± 37.77 min (group A), 390 ± 24.91 min in (group B) and 376.83 ± 26.79 min (group C). The prolongation of sensory block was highly significant in group A when compared to group B and C. Mean VAS score at 6 hrs in Group A was 1.37 ± 0.60, Group B 1.67 ± 0.76 and in Group C 1.87 ± 0.82. No complications due to the block or drugs used. Conclusion: Dexmedetomidine at the dose of 1 mcg/kg can be added to 0.75% ropivacaine, perineurally in lumbar plexus block effectively and safely.