In a total of 51 patients (26 with coronary heart diseases, 25 with primary myocardial diseases), the myocardial scintigrams after intracoronary particle injection (perfusion scintigraphy) and after intravenous nuclide injection with accumulation in the myocardium (thallium scintigraphy) were compared with each other and set against the coronary angiographic and levocardiographic findings. It was shown that extensive myocardial failures (aneurysms) can be represented by both nuclear medical procedures, but that perfusion scintigraphy is more sensitive and correlates more closely to the levocardiogram findings. Smaller abnormalities of contraction of the left ventricle (hypokinetic and akinetic areas) were always shown in the perfusion scintigram, more seldom in the thallium scintigram. The outstanding advantage of thallium scintigraphy is that it is non-invasive, it can be repeated as often as desired and is easily performed during ergometric stress.