Junctional tachycardias are among the most frequent or paroxysmal supraventricular tachycardias. They are due to a reentry mechanism and include the so-called nodal reentrant tachycardias as well as tachycardias which imply a patent or hidden accessory pathway. The prognosis of these tachycardias is usually benign, but it can be made unfavourable by repeated attacks or by the presence of an accessory pathway with short anterograde refractory period which exposes the patient to severe arrhythmia. Clinicians are now provided with a therapeutic armentarium that enables them to reduce easily any attack of junctional tachycardia, but also to prevent recurrences. The intracavitary ablation technique by application of radiofrequency currents ensures the radical cure of recurrent or threatening arrhythmias by suppressing the indispensable anatomical substrate of tachycardias.