Background: Intravenous acetaminophen is widely used in the management of postoperative pain. Opioids remain the agents of choice for severe pain; however, this class of analgesics is associated with dose dependent side effects and negative postoperative outcomes. Non-opioid analgesics are commonly used alone or as adjuncts to opioid-based analgesia to treat moderate to severe pain. The oral route for administration of drugs may be denied because of the nature of the surgery and drugs may have to be given by injection. Aims & Objectives: A single-dose, parallel group study was performed to evaluate the analgesic efficacy and safety of intravenous acetaminophen as compared with intravenous Fentanyl. The aim of this study was to evaluate the analgesic efficacy and safety of a single dose of 1 g of intravenous acetaminophen in comparison with 100 mcg of intravenous Fentanyl in patients experiencing pain after surgery. Methods: Patients (112) were selected who has received acetaminophen or Fentanyl. Pain intensity was assessed using WOMAC scale at 4 h after either of the drug administration. The secondary end point was Quality of Recovery (QoR) which was also assessed at 4 h after either of the drug administration. Safety was monitored through Side-effects reporting by patients. Results: The intravenous acetaminophen and intravenous Fentanyl groups differed significantly regarding Pain intensity score after single dose administration and at 4 h reading. As far as safety concern, Dry mouth is the major side-effect reported by patients in both the groups but it was higher Fentanyl group. Conclusion: Although acetaminophen is having low incidence of side effect as compared Fentanyl group but analgesic efficacy was much better in Fentanyl group than acetaminophen group. There were no significant differences in the QoR scale between two groups. We summarize how better postoperative pain management can be achieved with minimal side-effects and better recovery process.