Slow coronary flow (SCF) is the phenomenon of slow progression of angiographic contrast in the coronary arteries in the absence of stenosis in the epicardial vessels in some patients presenting with chest pain. There are no definite treatment modalities for patients with SCF. Our aim was to investigate the efficacy of nebivolol in patients with slow coronary flow by monitoring its effects on endothelial function and different markers of inflammation. Forty-two patients (16 females, 26 males; mean age, 55 ± 10) with slow coronary flow (SCF) were included in the study. After baseline assessment, the patients were administered nebivolol 5 mg once daily. After 12 weeks of nebivolol therapy, the biochemical and ultrasonographic examinations were repeated. Chest pain relief was detected in 38 patients after treatment (90%). Systolic and diastolic blood pressure and high sensitive CRP were significantly decreased after nebivolol therapy. Among brachial artery dilation variables that reflect endothelial function, basal resistive index (RI), post-flow mediated dilation RI, and post-nitrate mediated dilation RI were significantly decreased after therapy. Nebivolol is effective at improving endothelial function in patients with SCF. It controls chest pain, decreases CRP, and has favorable effects on brachial artery dilation variables in patients with coronary slow flow.