Data from experimental studies suggest that the f current-inhibitor ivabradine may reduce oxidative stress and improve endothelial function. We aimed to evaluate the effect of ivabradine on endothelial function in patients with coronary artery disease (CAD) after complete revascularization with percutaneous coronary angioplasty (PCI). At least 30days after PCI, 70 patients were randomized (T0) to receive ivabradine 5mg twice daily (ivabradine group, n=36) or to continue with standard medical therapy (control group, n=34). After 4weeks (T1), ivabradine dose was adjusted up to 7.5mg twice daily in patients with heart rate (HR) at rest >60bpm, and thereafter continued for additional 4weeks (T2). At all timings, brachial artery reactivity was assessed by flow-mediated dilatation (FMD) and nitroglycerin-mediated dilatation (NMD). No significant differences were observed at T0 between ivabradine and control groups in terms of HR (68.0±6.4 vs. 67.6±6.4bpm; p=0.803), FMD (8.7±4.9 vs. 8.0±5.5%; p=0.577) and NMD (12.7±6.7 vs. 13.3±6.2%; p=0.715). Over the study period, a significant reduction of HR (65.2±5.9bpm at T1, 62.2±5.7bpm at T2; p<0.001), and improvement of FMD (12.2±6.2% at T1, 15.0±7.7% at T2; p<0.001) and NMD (16.6±10.4% at T1, 17.7±10.8 at T2; p<0.001) were observed in the ivabradine group, while no significant changes were observed in the control group. In the ivabradine group, a moderate negative correlation was observed between the HR variation and FMD variation from T1 to T3 (r=-0.448; p=0.006). In patients with CAD undergoing complete revascularization with PCI, addition of ivabradine to the standard medical therapy produces a significant improvement in endothelial function. This effect seems to be related to HR reduction. ClinicalTrials.gov number, NCT02681978.