Background: Recently there has been an interest to explore the efficacy of nalbuphine as' an adjuvant to local anaesthetic agents. This study was designed to compare its analgesic efficacy when added to levobupivacaine in patients undergoing inguinal hernia surgeries under subarachnoid block. Methods: Fifty patients belonging to ASA I/II, between 18-65 years of age undergoing inguinal hernia repair were randomly allocated to receive subarachnoid block with either 12.5 mg of 0.5% isobaric levobupivacaine (2.5 ml)+ normal saline (0.5 ml) (Group-LS) or 12.5 mg of 0.5% isobaric levobupivacaine (2.5 ml)+ 1 mg nalbuphine (0.1 ml) + normal saline (0.4 ml) (Group-LN). Onset of sensory block, two segment regression time, time of regression to T12, duration of effective analgesia and intensity of motor block were assessed. Results: Onset of sensory block was comparable in the two groups (P=0.774). Time of regression of sensory block to T12 dermatome was 161.09 ± 40.50 min in group LS and 167.50 ± 50.17 min in group LN (P=0.633).The duration of effective analgesia was 177.39 ± 43.53 min in group LS and 183.75 ± 56.69 min in group LN (P=0.669).Motor block parameters were also comparable.More number of patients in group LN had a sedation score of one as compared to group LS.No major side effects were seen. Conclusion: 12.5 mg levobupivacaine with or without nalbuphine is sufficient for conducting inguinal hernia surgeries. Intrathecal nalbuphine 1 mg did not affect the sensory and motor block characteristics of levobupivacaine.