Twenty-three patients with resistant ventricular tachycardia not related to coronary artery disease underwent surgical treatment guided by ventricular mapping. The patients were grouped according to radiological and anatomical findings. Group 1 (13 patients) had arrhythmogenic right ventricular dysplasia. Group 2 (3 patients) had left ventricular aneurysm. Group 3 (2 patients) had nonobstructive myocardiopathy. Group 4 (5 patients) had normal-appearing hearts. At operation all patients underwent ventricular mapping when in sinus rhythm and during ventricular tachycardia. The rationale of operation was ventriculotomy or cryosurgery at the site of origin of ventricular tachycardia or exclusion, resection, or undermining of arrhythmogenic areas where delayed potentials were observed. Four patients died during the perioperative period, 3 of low-output failure and 1 from bleeding. Ventricular tachycardia recurred immediately after operation in 4 patients, 3 of whom died during the perioperative period. Ventricular tachycardia recurred late in 5 patients. Three had only episodic, unsustained runs of tachycardia. Two were well controlled by drugs. All patients with ventricular tachycardia situated over the free wall of the ventricles had inducible ventricular tachycardia and had good surgical results. Three out of 5 patients with ventricular tachycardia situated in the septum had poor surgical results. Septal ventricular tachycardia needs a better surgical approach to the septum and a suitable surgical concept.