Aims and objectives: To assess the effectiveness of duloxetine at various dosages for the management of postoperative pain in patients having lumbar spine surgery. Material and method: After being scheduled for lumbar spine surgery under general anaesthesia, 60 patients of both sexes with ASA grades I and II were randomly assigned to 2 groups, each with 30 members. Patients in Group D (n=30) were given two tablets of duloxetine, 90 mg one hour before to surgery and another the next morning. Patients in group "P" (n = 30) were given a placebo pill an hour before to surgery and again the morning after. After surgery, the following measurements were made: heart rate, blood pressure, breathing rate, and the intensity of pain on the NRS scale at 0, 4, 8, 12, 16, 20, 24, 28, 32, and 48 hours. Additionally, the occurrence or non-occurrence of side symptoms such headache, nausea, vomiting, dizziness, and sleepiness was recorded. Result: Analysis showed that when oral Duloxetine 90 mg was used instead of a placebo, the duration for the initial analgesic necessity was much longer. Pre-emptive oral Duloxetine 90 mg reduces postoperative pain intensity in patients undergoing lumbar spine surgery under general anaesthesia, although not much less so than a placebo. There was no discernible impact of 90 mg of oral duloxetine on respiratory or cardiovascular measures. Patients on duloxetine experienced nausea and vomiting more often. Conclusion: When taking 90 mg of oral Duloxetine instead of a placebo, the period before the need for a first analgesic was much longer.