Catheter ablation has evolved as the therapy of choice in patients with atrioventricular nodal reentrant tachycardia or atrioventricular tachycardia involving accessory pathways. Radiofrequency current catheter ablation is now generally accepted and most frequently used. In patients with ventricular tachycardia and no organic heart disease (idiopathic ventricular tachycardia) the success rates range between 80-90%. In addition, in patients with bundle branch reentrant tachycardia up to 100% success rates are described. The usefulness of radiofrequency ablation in patients with structural heart disease is still controversial. Although in patients with incessant ventricular tachycardia high acute success rates are observed, the results in post-myocardial infarction tachycardia or dilative cardiomyopathy range only between 40 and 75%. Further refinement of localization techniques as well as improvement of ablation technology is mandatory until the routine use of this technique as a curative procedure for ventricular tachycardia is defined.