Background A genetic correlation between Brugada syndrome (BS) and sinus node dysfunction (SND) has been proposed, although the clinical and electrophysiologic characteristics of this concomitant condition are unknown. Methods and Results The study comprised 5 patients with symptomatic BS (4 with spontaneous episodes of ventricular fibrillation (VF) and 1 with syncope) of whom 3 had a documented sinus pause >3 s (a 42- and 62-year-old man, and a 49-year-old woman). Only 1 of them had a family history of sudden death; 2 of them had also had an episode of atrial fibrillation or flutter. Electrophysiologic study demonstrated prolonged sinus node recovery time in 2 patients (2.6 s and >5 s), in whom a cardiac pacemaker had been implanted before the diagnosis of BS was made after episodes of VF. Finally, all 3 patients received an implantable cardioverter defibrillator, including 2 upgrades from pacemaker. Conclusions SND is not a rare concomitant disorder in BS and there is a possible genetic connection. (Circ J 2005; 69: 946 - 950)