Brugada syndrome is a clinical and electrocardiographic entity characterized by ST segment elevation in the right precordial ECG leads and sudden death or syncope secondary to malignant ventricular arrhythmia, and has a high recurrence rate. We report a patient with this syndrome who had received an automatic implantable defibrillator, who presented with multiple appropriate discharges because of recurrent episodes of ventricular fibrillation. All episodes were started by a premature ventricular beat of the same morphology and coupling interval. Endovenous procainamide administration, paradoxically, was effective in preventing new episodes. The beneficial antiarrhythmic effect of procainamide in this patient is discussed.