Objective: Behçet's disease (BD) is a chronic multi-system disease presenting with recurrent oral and genital ulceration, and relapsing uveitis. Left ventricular diastolic dysfunction, ventricular arrhythmia and sudden cardiac death have been documented in BD. P wave dispersion (PD) has been reported to be associated with inhomogeneous and discontinuous propagation of sinus impulses. PD has been reported to be longer in patients with BD. Nebivolol, besides its selective beta1-blocking activity, causes an endothelium dependent vasodilatation through nitric oxide release. In this study, we searched for the effects of nebivolol on P wave duration and dispersion in patients with BD. Methods: This study was designed as prospective single-arm controlled study. We prospectively studied 35 Behçet’s patients who were diagnosed according to the International Study Group criteria. Patients received 5 mg nebivolol per day for 3 months. The patients were evaluated with 12-leads electrocardiography at baseline and after for 3-month therapy. The difference between maximum and minimum P wave durations was defined as PD. The paired samples t test, Wilcoxon test were used for statistical analysis. Results: A significant decrease was observed in PD after therapy period (62.85±21.62 vs 44.28±18.03 msec, p=0.001). No adverse effects were observed in treatment period. Conclusion: BD is associated with prolonged P wave duration and dispersion. We have shown for the first time that nebivolol causes a significant decrease in maximum P wave duration and PD in patients with BD. However, further comprehensive studies are needed to determine the long-term effects of nebivolol.