BACKGROUND There are various adjuvants used along with bupivacaine but clonidine and fentanyl both prolong sensory and motor block and duration of analgesia. In this study we aim to evaluate the onset and duration of sensory and motor block, post-operative analgesia, and adverse effects of clonidine and fentanyl as an adjuvant with hyperbaric bupivacaine in patients of anorectal surgery. METHODS This prospective randomized controlled trial was performed among 60 patients of either sex, aged 18-60 years who belonged to ASA I to III. Group I (BF) received 0.5% hyperbaric bupivacaine (0.5 ml) and fentanyl (15 μg) and Group II (BC) received 0.5% hyperbaric bupivacaine (0.5 ml) and clonidine (30 μg). The onset and duration of sensory and motor block, post-operative analgesia, VAS score, hemodynamic parameters, sedation and adverse effects were recorded and analysed. RESULTS The onset of sensory block was comparable in group BF (8.83 ± 1.62) and group BC (8.16 ± 1.37). The onset of motor block was faster in group BC (8.90±1.24) as compared to group BF (9.70 ± 1.66). The mean time for 2 segment regression, duration of sensory block and duration of motor block were significantly lower (<0.001) in group BC as compared to group BF. CONCLUSIONS Low-dose of intrathecal clonidine as an adjuvant to hyperbaric bupivacaine provided prolonged duration of sensory block and postoperative analgesia with more sedation as compared to intrathecal fentanyl.