This report describes the multicenter experience of the Tachylog antitachycardia pacemaker (Siemens-Elema) in the treatment of drug-refractory, recurrent supraventricular arrhythmias. The device has been implanted in 63 patients (mean age 47 years). The arrhythmias were atrial tachycardia in 4 patients (6%), atrioventricular nodal reentry tachycardia in 23 patients (37%), circus movement tachycardia via an overt bypass tract in 17 patients (27%) and via a concealed bypass tract in 19 patients (30%). The mean follow-up period was 30 months. In 28 patients (44%) arrhythmia control was achieved with the pacemaker therapy alone. In 31 patients (49%) drug therapy had to be reintroduced to obtain control of recurrent arrhythmias. Four patients (6%) were definite nonresponders. In 4 patients (6%) the pulse generator was explanted either because it was not tolerated or because of tachycardia-sensing failure. No syncope or death was observed during follow-up. Thus, antitachycardia pacing gives satisfactory results in selected patients with drug-refractory supraventricular tachycardias.