Three forms of discrete sub-aortic Stenosis have been recognised and described. A long tunnel-like narrowing of the left ventricular outflow tract was the most severe form and was recognized as different from hypertrophic obstruction cardiomyopathy (HOCM). Sixty patients with discrete sub-aortic Stenosis have been operated on with enucleation of the Stenosis during the past 15 years at the National Heart Hospital, London, and followed-up for up to 14 years. Overall there were 4 hospital deaths (6.6%) and only one late death. Emphasis has been placed on the superiority of blunt dissection in the enucleation of the entire, discrete Stenosis when contrasted with the conventional Sharp dissection technique which may well lead to subsequent accretions of obstructive thickening. The surgical enucleation of the discrete sub-aortic Stenosis has been an entirely satisfactory procedure from a hemodynamic viewpoint and carries a low operative risk with every possibility of a subsequent event-free follow-up.