Adjuvants prolong the action of intrathecal local anesthetic agents. They have shown to have significant analgesic effects in the postoperative period much after the regression of the sensory and motor blockade. Our objective of the current study was to compare the hemodynamic profile and adverse effects (nausea, pruritus, sedation and respiratory depression) in two groups of adult patients undergoing infra-umbilical and lower limb surgery under spinal anesthesia using either intrathecal clonidine or intrathecal fentanyl as an adjuvant to intrathecal bupivacaine (0.5% heavy).