Ranolazine is an antianginal agent, which inhibits the abnormal inward Na(+) current and by this inhibition decreases diastolic cardiomyocyte calcium levels and improves electrical stability. Ranolazine has also been shown to be a potent inhibitor of after depolarizations and triggered activity. In this case report, we describe the dramatic antiarrhythmic effects of ranolazine in a patient with nonischemic cardiomyopathy who had malignant ventricular tachycardia. Further research on the antiarrhythmic properties of ranolazine appears warranted.