The timing of operation is discussed for aortic, mitral, and combined aortic and mitral insufficiency. The effect of surgical mortality on selection is assessed on the basis of the Green Lane Hospital results for valve replacement in the current cardioplegic era. Particular attention is paid to the effect of the preoperative symptomatic status. The criteria for selection of the patient who is essentially asymptomatic are documented in detail. It is concluded that they differ, depending upon whether there is aortic incompetence, mitral incompetence, or incompetence of both valves. The effect of the type of valve used for replacement on case selection includes an up-to-date assessment of the results achieved with freehand aortic homograft valve replacement.