AbstractIntroduction: Bupivacaine (0.5% heavy) is used to administer subarachnoid block but carries an increased risk of cardiac and central nervous system toxicity if inadvertently injected intravascularly. Levobupivacaine is S-enantiomer of racemic bupivacaine with lesser systemic toxicity. A study was done to compare isobaric levobupivacaine and hyperbaric bupivacaine for spinal anaesthesia in patients undergoing elective lower abdominal surgeries to study hemodynamic variations, sensory and motor blocking properties of these. Methods: A prospective randomized controlled double blind study was conducted in 100 patients of ASA I and II physical status posted for elective lower abdominal surgeries under subarachnoid block, randomized into 2 groups with 50 patients each, received either 3 ml of 0.5% isobaric levobupivacaine (group L) or 3 ml of 0.5% hyperbaric Bupivacaine (group B). Hemodynamic parameters, time for onset of sensory and motor blockade, maximum height of sensory block and total duration of sensory and motor blockade were recorded. Intraoperative or postoperative side effects were noted. Results: The incidence of hypotension and bradycardia were comparable between the two groups. Onset of sensory and motor block (L-2.88 ± 1.81, B-2.12 ± 0.47, p value 0.005, L-3.12 ± 1.62, B-2.28 ± 0.81, p value 0.001, respectively) were significantly delayed in levobupivacaine group. The total duration of sensory block (L- 190.04 ± 35.19, B- 204.02 ± 30.06, p value 0.035) and motor block (L-176.65 ± 40.64, B 204.46 ± 29.8, p value<0.001) were higher in bupivacaine group. Conclusion: 0.5% isobaric levobupivacaine could be an alternative to 0.5% hyperbaric bupivacaine for spinal anaesthesia with similar hemodynamic changes, side effects and shorter durations of sensory and motor blockade.