PURPOSE: To determine the effects of intraoperative dexmedetomidine (DEX) administration on postoperative ischaemia/reperfusion injury (HIRI) and clinical outcomes of patients undergoing the laparoscopic living donor hepatectomy (LLDH). PATIENTS AND METHODS: Fifty-five patients who underwent the LLDH were randomly assigned to the DEX or control group. The DEX group received an intravenous infusion of DEX with an bolus dose of 1 µg/kg for 15 min before anaesthesia induction, followed by a continuous infusion at a rate of 0.4 µg/kg/h until the portal branch was disconnected. The control group was given an intravenous infusion of 0.9% saline at same volume and rate. The primary outcome was peak serum aspartate aminotransferase (AST) level during the first 72 h postoperatively. The secondary outcomes included other variables of postoperative liver and kidney function, intraoperative hemodynamic changes, postoperative recovery outcomes and the occurrence of complications. RESULTS: The peak serum AST level during the first 72 h postoperatively was not significantly different between groups (DEX vs control: 288 [194-466] vs 324 [194-437] IU/L; difference, -1.2 IU/L; 95% CI, -86.9 to 88.0; =0.973). The intraoperative mean artery pressure was not significantly different, but intraoperative heart rate was significantly decreased in the DEX group. There were no significant differences between groups in other secondary outcomes. CONCLUSION: This study demonstrates that intraoperative DEX administration at the studied dosage regimens cannot attenuate postoperative HIRI and does not improve clinical outcomes in patients undergoing the LLDH. CLINICAL TRIAL REGISTRATION: www.chictr.org.cn, ChiCTR2000040629.