One-hundred-and-three patients underwent surgery for paroxysmal supraventricular tachycardia (PSVT). In eighty-three patients (81%), PSVT was due to an accessory atrioventricular pathway (Group I) and in 20 (19%) to Atrioventricular Junctional (AV nodal) Reentrant Tachycardia (AVJRT:Group II). Initial surgery successfully divided 77 of 83 accessory pathways, including 58 of 60 left free wall pathways, 12 of 15 posteroseptal pathways, six of seven right free wall pathways and one anteroseptal pathway. Twenty patients had successful surgery for AVJRT. Surgery was performed with low morbidity and no early or late mortality in either group. One patient in each group required permanent pacemaker implantation. Immediate (within one week) postoperative electrophysiological study using epicardial wires was performed in 96% of patients and repeat electrophysiological study six months later was possible in 65/103 (63%) patients. Patients with surgery for accessory pathways were followed-up for a mean 34 +/- 23 months, while those with surgery for AVJRT for a mean of 13 +/- seven months. No patient with successful surgery has had a clinical recurrence of PSVT. Thus the results indicate that surgery is a safe and curative therapy for patients with PSVT.