This study was performed, i) to compare radionuclide angiocardiography with the other methods, and ii) to evaluate its usefulness in investigating left ventricular performance and its reserve. Radionuclide angiocardiography, chest X-ray film, chest X-ray cinegraphy, echocardiography, two-dimensional echocardiography, pulsed Doppler flowmetry, cardiokymography, myocardial imaging, contrast ventriculography and coronary arteriography were performed (:also at exercise) in 105 subjects including various kinds of cardiac patients. Radionuclide angiocardiography could be performed both at rest and at exercise, contrary to invasive methods. In detailed analysis of left ventricular mechanics in non-ischemic heart disease, echocardiography at rest and at exercise may be appropriate, because of its high image resolution. In evaluation of ischemic heart diseases, radionuclide angiocardiography at rest and at exercise might be appropriate, because of bidirectional informations and its high success rate. Two-dimensional echocardiography with M-mode echocardiography might compensate for it, particularly for continuous informations during exercise. Detection of regional wall motion dysfunction at exercise is more specific than exercise ECG and is more sensitive than exercise myocardial imaging. From many kinds of examinations, appropriate one should be selected according to the purpose of investigators. Much more technical progress in these methods can be expected.