Currently available diagnostic methods and surgical technics now allow accurate assessment and effective correction of the majority of lesions producing obstruction of the left ventricular outflow tract. On the basis of anatomic location these lesions can be divided into supravalvular, valvular, and subvalvular stenosis, and valvular lesions further can be subdivided into congenital and acquired categories. Temporary cardiopulmonary bypass with a pump oxygenator provides sustained support of the circulation for operation, while surgical technics employed are selected on the basis of etiology and location of the lesion. Experience gained in operations on 296 patients with obstructive lesions of the left ventricular outflow tract since 1956 now has demonstrated that these operations usually can be performed with acceptable risk and with excellent functional results.