BACKGROUND: Lack of proper control of acute postoperative pain often leads to lingering or chronic pain. Several studies have emphasized the role of beta-blockers in reducing postoperative pain. Esmolol is a selective short-acting beta-blocker that produces few side effects. The purpose of this study was to examine the effect of intravenous intraoperative esmolol on postoperative pain reduction following orthopedic leg fracture surgery. METHODS: In a clinical trial, 82 patients between 20-65 years of age with tibia fractures and American Society of Anesthesiologists (ASA) physical status I & II who underwent surgery were divided into two groups. Group A received esmolol and group B received normal saline. Postoperative pain was measured at three time points: entering the recovery unit, and at 3 h and 6 h following surgery, using the Visual Analogue Scale (VAS). A P value of < 0.05 was considered significant. RESULTS: Mean VAS scores at all three time points were significantly different between the two test groups (P = 0.02, P = 0.0001, and P = 0.0001, respectively). The consumption of pethidine was lower in group A than in group B (P = 0.004) and the duration of its effect was significantly longer in time (P = 0.026). CONCLUSIONS: Intravenous intraoperative esmolol is effective in the reduction of postoperative pain following leg fracture surgery. It reduced opioid consumption following surgery and delayed patient requests for analgesics.