Pain is an unpleasant sensory and emotional experience causes due to tissue damage, which is now used as the fifth vital signs. However, nowadays pain management options are not few, but still, physicians are incapable towards effective control of acute pain, especially postoperative pain. Opioid analgesics are often used for this purpose, which is associated with high risk of side effects. Thus, we are all in search of an alternate method to control pain to reduce the risk of side effects associated with the use of opioids. The present study was conducted on 60 patients randomly divided into two groups (A & B), who underwent laminectomy in Jahrom Peymanieh Hospital. Group A (n = 30) patients received single dose of 30 mg intravenous ketorolac at first and followed by 15 mg intravenous ketorolac at every 6 hours gap for 24 hours. Group B (n = 30) patients received 5mg intramuscular (IM) ketorolac at first and followed by the same dose at every 6 hours for 24 hours. Pain Questionnaire Visual Analog Scale (VAS) and vital sign were evaluated before and after administration of analgesic every 6 hours for 24 hours. Data were collected using questionnaires and analyzed in SPSS18. The results showed that intravenous Ketorolac compared to IM Methadone is more effective in the management of acute postoperative pain and has less complications and less physical dependency. However, unlike methadone, ketorolac did not decrease postoperative morphine usage.