Fifty patients have been operated upon for the tachyarrhythmias associated with Kent bundles. The indications for operation were supraventricular tachycardia (SVT) in 23 and life-threatening tachyarrhythmia in 27. Among the unusual variants noted were multiple Kent bundles that conducted only retrograde in 3. Forty-nine patients underwent attempted interruption of the bundle of Kent followed by His bundle division in 6. One had elective division of the bundle of His. The surgical problems occurred in 13 patients with posterior septal Kent bundles. A new approach is outlined for this group. Division of the Kent bundle was successful in 31 patients, but 2 deaths occurred from cardiomyopathy. Seven patients had successful control of SVT by His bundle interruption. One patient with postoperative retrograde conduction has the SVT controlled with drugs. Eight have postoperative delta waves, but their SVT is controlled with drugs. There were 3 failures.