A total of five patients were operated upon for subaortic stenosis due to fibromuscular hypertrophy, using a generous left ventriculotomy centered on the apex. There were no deaths or serious complications, and all patients showed a completely satisfactory functional result in the postoperative periods of 19, 17, 11, 8, and 7 months. Three patients recatheterized 16, 11, and 7 months after surgery were found to have a virtual abolition of the gradient. Pressure measurements made at the completion of surgery in all patients, indicated satisfactory removal of the obstruction. The excellent exposure afforded by this ventriculotomy and the absence of complications arising from its use, recommend it for continued trial. It must, however, stand comparison with other techniques on the basis of the durability of the relief of obstruction.