After more than 20 years of clinical use, programmed electrical stimulation for induction of cardiac arrhythmias remains an important clinical and research tool. The procedure continues to undergo refinement but is not without controversy regarding its accuracy in predicting drug efficacy as determined by serial testing for suppression of ventricular tachyarrhythmias. Recent work has streamlined technical aspects of the procedure itself and promises to improve the selection of patients likely to benefit from such studies. Despite these advances, however, recent publications from the Electrophysiologic Study Versus Electrocardiographic Monitoring trial raise fundamental questions about the ability of any current strategy to predict the efficacy of antiarrhythmic drugs for the prevention of ventricular arrhythmias.