The value of programmed electrical stimulation (PES) and Holter monitoring in the assessment of amiodarone efficacy was reviewed. Many physicians have been disturbed by the persistent inducibility of arrhythmias in patients treated with amiodarone, who nevertheless do very well during the follow-up period. Noninducibility was associated with a favorable prognosis among 366 VT patients. Eighty-eight (24%) were noninducible on amiodarone, and 10% of these had recurrences, vs 39% in patients who remained inducible. Further, increased difficulty of induction with PES or induction of a slower or better tolerated VT may indicate a favorable outlook, and add to the value of PES. Few papers rigorously employed Holter monitoring in the assessment of amiodarone. In general, suppression of previously frequent arrhythmias implies excellent protection for patients with benign arrhythmias and moderate protection with malignant arrhythmias. By Holter assessment in 186 VT patients, arrhythmias were suppressed in 114 (61%), and 18% of these had recurrences vs 50% in patients whose arrhythmias were not suppressed. Studies attempting to correlate the results of PES and Holter monitoring in the same patients are lacking and may prove useful.