BACKGROUND AND OBJECTIVES: Intravenous nicorandil infusion with percutaneous coronary intervention (PCI) has been reported to reduce reperfusion injury events and to improve cardiac function in patients with an acute myocardial infarction. However, there is limited information on the use of intra-coronary nicorandil. A prospective randomized single center study was designed to evaluate the efficacy of the use of intra-coronary nicorandil. SUBJECTS AND METHODS: Seventy-three patients with an acute ST segment elevation myocardial infarction were randomly assigned to the nicorandil group (n=37) or a control group (n=36); all patients received a PCI. In the nicorandil group of patients, 4 mg of intra-coronary nicorandil was infused directly into the infarct area prior to reperfusion (2 mg before ballooning, 2 mg before stenting). The composite endpoint was the incidence of ventricular arrhythmia, no-reflow and slow flow. We estimated the post thrombolysis in myocardial infarction (TIMI) grade, the myocardial perfusion grade after PCI and the short-term clinical outcome. RESULTS: The baseline characteristics were similar in both groups of patients. A significant difference was observed in the composite endpoint in the nicorandil group of patients as compared to the control group of patients (p=0.037). The achievement rate of post TIMI grade 3 was significantly higher in the nicorandil group of patients (p=0.019). The myocardial perfusion grade 1 was not observed in the nicorandil group of patients; however, it was observed in five patients in the control group (p=0.019). Major adverse cardiac events in hospital and in 30 days were similar between the two groups. CONCLUSION: Intra-coronary nicorandil infusion reduced the occurrence of no-reflow, slow reflow, reperfusion arrhythmia and improved the myocardial perfusion grade and TIMI flow during PCI. The results of this study showed that the use of intracoronary nicorandil improved the clinical outcome in patients with an acute myocardial infarction.