The feasibility of cinefluoroscopic grading of coronary calcification was tested for differential diagnosis of ischemic cardiomyopathy (IMD) and non-ischemic myocardial disease (N-IMD) simulating dilated cardiomyopathy (DCM). Twenty-seven patients with generalized hypokinesis of the left ventricle but without localized infarction or aneurysm on two-dimensional echocardiography were categorized as Group A of 17 cases examined by both cinefluoroscopy and coronary cineangiography (CAG); Group B, 10 examined only by noninvasive method because of severe congestive heart failure, old age or poor renal function. Cinefluoroscopy was recorded on 35 mm cinefilm for review using a 7 inch image intensifier, 2 to 3 mA and 90 to 100 kV, in the anteroposterior, right and left anterior oblique, and left lateral projections. We judged the degree of coronary calcification as Grade 1, calcification difficult to recognize; Grade 2, easily recognized; Grade 3, recognized in more than half of one coronary artery; and Grade 4, recognized in nearly the entire length of one coronary artery. To obtain the calcification score, the degree was multiplied by the number of calcified main coronary branches. IMD was defined as more than 75% decrease in the diameter of either the left main coronary artery or any other two major coronary vessels. I. The results obtained for group A were: 1. All six cases of IMD had coronary calcification. 2. The score of IMD was 21.2 +/- 8.1; that of N-IMD, 0.18 +/- 0.39. 3. The minimum IMD score was 10 without evidence of any calcification in the non-dominant right coronary artery. 4. Among three cases of DCM, two scored 1 and one scored 0. 5. The sensitivity and specificity of calcification for IMD were 100% and 81.8%, respectively. II. The following results were obtained in Group B, if IMD was defined as score more than 10. 1. The mean score of three IMD cases was 28 +/- 1.4, and the diagnosis was confirmed by subsequent CAG in two of them. 2. In none of the five N-IMD cases, calcification was recognized. The diagnosis of one case was confirmed by subsequent CAG. 3. The diagnosis was not confirmed in two cases who had score 3. These results indicate that calculated scores based on the severity of coronary artery calcification documented cinefluoroscopically can differentiate IMD from N-IMD both inexpensively and noninvasively.