['The primary purpose of the study was to evaluate long-term clinical results of radiofrequency catheter ablation of accessory pathway-mediated tachycardia.', 'Catheter ablation was performed in 321 patients who were subsequently followed up for an average of 36 months.', 'Accessory pathway-mediated tachycardia was abolished by catheter ablation in 308 patients (96%). Right free wall (10.6%) and right posteroseptal (14.9%) accessory pathway was associated with higher failure rate than left-sided pathways (2.3%, p<0.01). Atrioventricular block occurred in two patients during ablation of anteroseptal pathway. Recurrence of accessory pathway conduction occurred in 13 (4.1%) patients, principally within the first 4 weeks after ablation procedure. Recurrence in right free wall (12.8%) or right posteroseptal (14.2%) pathways was higher than in left-sided pathways (1.8%, p<0.01).'] Is radiofrequency catheter ablation of accessory pathway-mediated tachycardia a safe and effective long-term therapy?