Aim: The aim of the study to compare a combination of isobaric Levobupivacaine with fentanyl and dexmedetomidine for the characteristics of spinal blockade with respect to onset, duration and hemodynamic parameters and side effect. Methods: This was a prospective, randomized, and double blinded clinical comparative study conducted in the Department of Anaesthesia, Vardhman Institute of Medical Science (VIMS), Pawapuri, Nalanda, Bihar, India for 14 months. The study population consisted of 210 adult patients who were classified as American Society of Anesthesiologists (ASA) physical status I or II, undergoing elective lower limb orthopaedic surgery under spinal anesthesia. The study participants were randomly divided into three groups. Group A: 0.5% Levobupivacaine Isobaric 2.5ml+ 0.5ml normal saline (total volume is upto 3.0 ml). Group F: 0.5% Levobupivacaine Isobaric 2.5ml + 25mug fentanyl (test solution will diluted with normal saline to total volume of 3.0ml). Group D: 0.5% Levobupivacaine isobaric 2.5ml +5 mcg dexmedetomidine (test solution will diluted with normal saline to total volume of 3.0 ml. Result: The mean time for onset of sensory block was 11.04 ±4.21 min in the saline group and 8.76±2.99 min in the dexmedetomidine group and 2.28±1.42 min in the fentanyl group. The mean time taken to achieve maximum sensory block in group A was 16.18±4.83 min, in group D was 14.16±3.42 min and in group F it was 5.52±1.67 min so maximum sensory block was achieved earlier in group. Peak level of sensory block attained in the fentanyl group was T4 and the peak level of sensory block in dexmedetomidine group was T6 and in the saline group peak level was T8. So the highest sensory block was attained in the fentanyl group. The mean duration of sensory block in group A was 115.63±7.15min, and in group F was 163.32±12.74min, and in group D was 206.17±6.42 min. Prolong duration occur in the dexmedetomiine group. Conclusion: Dexmedetomidine group has longer onset of and duration of sensory block and effective postoperative analgesia and fewer side effects as compared to fentanyl group.