INTRODUCTION: When the intrathecal opioid drug was administered with the local anaesthetic in Spinal anaesthesia they develop the superior quality of analgesia. Fentanyl was found to provide safe potentiate of local anaesthetic effects by its increased lipophilic quality and decreased rostral spread. The present study was conducted to compare block characteristics of equal doses of isobaric levobupivacaine 0.5% (10 mg) with normal saline and isobaric levobupivacaine 0.5% (10 mg) plus fentanyl (25 μg), in infraumbilical surgeries under spinal anaesthesia. MATERIALS AND METHODS: The present prospective observational study was conducted in tertiary health centre from January 2020 to June 2021 amongst 120 patients belong to ASA physical status I and II aged between 20 to 65years who underwent infraumbilical surgeries. Study population were divided into Group L: Group of 60 patients received 2 ml of 0.5% isobaric levobupivacaine (10 mg) plus 0.5 ml normal saline and Group LF: Group of 60 patients received 2 ml of 0.5% isobaric levobupivacaine (10mg) + 0.5 ml fentanyl (25 μg). RESULTS: The mean time for onset of sensory blockade at T10 dermatome in group L (7.1±1.4 min) was late than in group LF (5±1.6 min). Higher dermatomal level of sensory blockade was achieved by addition of fentanyl. The mean time for maximum sensory blockade was earlier in group LF (8.1±1.7min) than in group L (15.6±2.1min.). Maximum motor blockade was achieved significantly earlier in group LF than group L. The total duration of sensory blockade was significantly prolonged in group LF than in group L.Total duration of analgesia in group L was 199.2 ± 10.7 min and in group LF was 263.2 ± 14.7 min. CONCLUSION: It was concluded that addition of fentanyl to levobupivacaine leads to early onset of sensory blockade and prolonged duration of sensory blockade, motor blockade, stable hemodynamics and prolonged postoperative analgesia thus decreasing the doses of rescue analgesics.