Context:Intrathecal administration of levobupivacaine with fentanyl and levobupivacaine with magnesium sulfate for postoperative analgesia.Aim:To compare the quality and duration of postoperative analgesia by addition of fentanyl or magnesium sulfate to levobupivacaine given intrathecally.Setting and design: The study was conducted as a Randomized, Double–Blinded, Controlled Study in a 1200 bedded teaching hospital.Materials and methods:60 patients undergoing lower abdominal surgery were randomly divided into two groups 30 each, group LF received 12.5 mg of 0.5% isobaric levobupivacaine with 25mcg fentanyl. Group LM received 12.5 mg of 0.5% isobaric levobupivacaine with 25mg of magnesium sulfate. Onset of sensory and motor block, duration and quality of analgesia was noted along with intraoperative hemodynamic parameters.Statistical analysis: Microsoft Excel 2010 with student ‘t’ test (unpaired) and one way ANOVA were used for comparing the two groups.Results:The addition of fentanyl to levobupivacaine prolonged the duration of sensory block(LF 235.83±18.10 vs LM 205.17±19.14),motor block(LF 190.5±13.60 vs LM 152.47±10.63) and duration of analgesia(LF 287.5±16.12 vs LM 246.33±19.38) compared to MgSO4 with p<0.05 found statistically significant.Conclusion:Intrathecal levobupivacaine plus fentanyl prolonged the duration of sensory and motor block and provided prolonged duration of analgesia.