Background: Inadequate postoperative pain relief can delay recovery, increase healthcare costs and reduce patient satisfaction. Some studies revealed that spinal bupivacaine-dexamethasone had almost the same analgesic potency as bupivacaine-fentanyl with opioid-sparing and antiemetic effects. The optimum dose of spinal dexamethasone for postoperative analgesia has not been yet evaluated. So, it became mandatory to conduct a study clearing the safety and the optimum dose of spinal dexamethasone for postoperative analgesia in patients undergoing abdominal hysterectomy