The AA. reviewed our experience concerning 64 patients operated on for discrete subaortic stenosis due to a fibrous membrane, between 1975 and 1981 at the Department on Cardiac Surgery "A. De Gasperis" in Milan. The clinical and hemodynamic features, the indication for operation, the surgical management and the immediate and long-term results are described. No patients died at surgery or afterwards. Only in three cases complications were noted (2 atrioventricular block, 1 pleural empyema). Of all the patients 95% were asymptomatic after operation; only three cases presented symptoms correlated with the cardiac malformation, but still they were greatly improved, compared to their preoperative status. As discrete subaortic stenosis is a progressive disorder, the operative risk is poor and the results are good, surgical treatment is recommended in symptomatic patients and if the haemodynamic gradient is 50 mmHg or greater.