Arrhythmias and sudden death are well-recognized complications that occur late after correction of tetralogy of Fallot. This study, based on the literature and personal work, reviews the numerous investigations prompted by these complications and provides recommendations regarding follow-up. Conduction disturbances and ventricular arrhythmias are both common; although mostly asymptomatic, they are the likely cause of syncopy and sudden death. Supraventricular arrhythmias are less common but cause symptoms more frequently. Detecting patients at risk for life-threatening arrhythmias is an important task. The simple surface electrocardiogram (ECG) gives a host of information regarding patients at risk. Holter recordings, signal-averaged ECG, and invasive electrophysiological studies may all be helpful; the indications to perform these investigations are discussed and propositions are made for the follow-up of the postoperative patient. There is hope that a systematic approach along these lines, together with surgery done at an earlier age, will decrease the incidence of severe arrhythmias and sudden death in the future.