Treadmill stress testing has many applications in the overall evaluation of ischemic heart disease, both as a diagnostic aid and as an aid in serially following patients under study. Its use in the evaluation of procedures designed to improve myocardial function and coronary perfusion is of great value, for it can supply objective evidence without recourse to more difficult procedures such as determination of blood lactate levels. Ancillary procedures which may complement treadmill stress testing may prove to be valuable additions to the study of ischemic heart disease. The reported high rate of false-positive Master two-step tests would tend to make the treadmill exercise test more attractive.