Many liver transplant recipients experience intraoperative hyperglycemia after graft reperfusion. Accordingly, we introduced the Portland intensive insulin therapy (PoIIT) in our practice to better control blood glucose concentration (BGC). We evaluated the effects of PoIIT by comparing with our conventional insulin therapy (CoIT). Of 128 patients who underwent living donor liver transplantation (LDLT) during the phaseout period of CoIT, 89 were treated with the PoIIT and 39 were treated with CoIT. The primary outcome was hyperglycemia (BGC > 180 mg/dL) during the intraoperative postreperfusion phase. The secondary outcomes were postoperative complications such as infection. The incidence of hyperglycemia (22.5% vs. 53.8%, p = 0.001) and prolonged hyperglycemia for >2 hours (7.9% vs. 30.8%, p = 0.002) was significantly lower in PoIIT group than in CoIT group. A mixed linear model further demonstrated that repeatedly measured BGCs were lower in PoIIT group (p < 0.001). The use of PoIIT was significantly associated with decreases in major infections (OR = 0.23 [0.06–0.85], p = 0.028), prolonged mechanical ventilation (OR = 0.29 [0.09–0.89], p = 0.031), and biliary stricture (OR = 0.23 [0.07–0.78], p = 0.018) after adjustments for age, sex, and diabetes mellitus. In conclusion, the PoIIT is effective for maintaining BGC and preventing hyperglycemia during the intraoperative postreperfusion phase of living donor liver transplantation with potential clinical benefits.