The results of surgical procedures for treatment of supraventricular tachycardias were assessed in 65 patients undergoing operation between January, 1980 and December, 1993. Indications for intervention were WPW (59 patients), atrial fibrillation (5 patients) and atrial flutter (1 patient). All cases of WPW were refractory to medical treatment and 14 of 58 patients had one or several syncopes, 4 of whom had to be resuscitated. The surgical treatment of these patients was dissection of an accessory atrioventricular pathway. 15 of these patients underwent heart operation for a different indication at the same time. A total of 60 accessory pathways were diagnosed preoperatively, while 4 were located intraoperatively. The reoperation rate was 3% (2 patients) due to persistent WPW. Incidence of total AV block after the operation was 7% (4 patients). In the late postoperative stage, 12 patients developed supraventricular tachycardias, but none of these cases required surgical treatment. The actuarial survival rate after 10 years was 100%, and after 14 years 96%. We conclude that surgical dissection of accessory pathways offers a good alternative in cases of unsuccessful catheter ablative procedures or in cases of concomitant heart surgery. In 6 patients with mitral valve surgery, associated chronic atrial fibrillation was found. A concomitant Maze-procedure was performed for the purpose of surgically converting the atrial fibrillation to a stable sinus rhythm. The early postoperative results are promising.