A 41-year-old man with Brugada syndrome (BS) and no previous episodes of aborted sudden death or syncope referred to local emergency room for an episode of symptomatic atrial fibrillation. Blood chemistry results showed hypokalemia (2.9 mEq/L). The other parameters were within the normal range. After few minutes, an episode of ventricular fibrillation treated with biphasic DC shock 150 J occurred. In successive 2 hours, the patient experienced recurrent episodes of ventricular tachycardia and fibrillation. Each biphasic DC shock 150 J was effective to restore sinus rhythm. No further episodes occurred after normalization of serum levels of potassium. Before discharge, an implantable cardioverter defibrillator was inserted to prevent sudden cardiac death. Hypokalemia increases the risk of arrhythmic events in BS.