Dexmedetomidine(DXM), a selective 2-adrenoreceptor agonist, has been used in the epidural space in humans without any reports of neurological deficits. Previous clinical studies showed that intravenous dexmedetomidine administration prolonged the sensory and motor blocks of bupivacaine spinal analgesia. But clinical studies about the use of intrathecal DXM with local anesthesia in humans are scarce in the literature. Kanazi et al. found that 3μg DXM added to 12 mg spinal bupivacaine produced the significant short onset of sensory and motor block as well as significantly longer duration of sensory and motor block than bupivacaine. And Al-Mustafa et al. reported that intrathecal dexmedetomidine as an adjuvant to 12.5mg bupivacaine in spinal anesthesia has a dose dependant effect on the onset and regression of sensory and motor block.