Two cases of documented torsade de pointes ventricular tachycardia in association with the use of disopyramide are described. One patient had previously experienced an episode suggestive of quinidine induced ventricular tachycardia while the other developed ventricular tachycardia during quinidine treatment which was later exacerbated and sustained by the administration of disopyramide. Both patients exhibited a prolonged QTc or QUc interval at the time of the arrhythmia. These cases suggest that a propensity of ventricular arrhythmias induced by quinidine may identify individuals who are likely to develop similar arrhythmias disopyramide treatment as well.