A 17-year-old man was referred to our hospital for treatment of common paroxysmal atrial flutter. His electrocardiogram at rest showed subtle ST-segment elevation in leads II, III, and aV(F). Intravenous pilsicainide caused further ST-segment elevation in the inferior leads, new ST-segment depression in leads V2-V6, two distinct forms of premature ventricular complexes (PVCs) triggering short runs of polymorphic ventricular tachycardia (VT). An infusion of isoproterenol suppressed these arrhythmias and normalized the ST-segment. Pilsicainide may induce PVCs and polymorphic VT in atypical Brugada syndrome.