Résumé : The accessory bypass tracts are responsible for many episodes of supraventricular arrhythmias in man. The Wolff-Parkinson-White syndrome is the best example. These arrhythmias can be refractory to the medical treatment and are sometimes lethal. Different techniques can be used to destroy these pathways. The surgical dissection is the most widely accepted technique. The accessory pathways are made of working muscle and are neither visible, nor palpable by the surgeon. The electrical properties of these pathways are used to localize them. These techniques are either non-invasive or invasive. The non-invasive techniques consist of the careful analysis of the surface electrocardiogram in sinus rhythm and during tachycardia. The invasive techniques consist of a pre-operative electrophysiological study and intra-operative mapping. The electrophysiological study consists of the introduction of multiples catheters inside the heart through peripheral veins. The intra-operative mapping consists of measurements done on the surface or inside the heart after the chest has been open. After precise localization of the areas of insertion of these abnormal tracts the surgeon proceeds with the dissection, starting either on the epicardial or on the endocardial side of the heart. The surgical results are excellent and there are only few complications. These techniques were used to operate six patients presenting with the Wolff-Parkinson-White syndrome.