Background: Ibutilide is a class III antiarrhythmic drug that is used for the cardioversion of atrial arrhythmias, but it can cause torsades de pointes. Amiodarone is also used for the cardioversion of atrial fibrillation and prolongs the QT interval but rarely causes torsades de pointes. Methods and Results: The study included 51 consecutive patients with recent onset atrial fibrillation in whom the administration of ibutilide failed to restore sinus rhythm. In those patients we decided to proceed to intravenous administration of amiodarone. The QT intervals were measured on 12-lead ECG. After 11 ± 5 h of the administration of the amiodarone, 42 patients (82%) were on sinus rhythm. There was no episode of non-sustained torsades de pointes or hypotension that followed the administration of the two antiarrhythmic agents. Conclusions: The administration of amiodarone in the case of ibutilide failure may be a useful adjunct to current cardioversion protocols for recent onset atrial fibrillation.