It has been known that dilated cardiomyopathy(DCM) is characterized by systolic dysfunction of left ventricle(LV), but there were few studies about correlation between LV systolic function, diameter and diastolic function measured by echocardiography and radionuclide ventriculography(RVG) The purpose of this study is to evaluate LV systolic and diastolic function as well as RV function using regional ejection fraction and functional images by RVG in 17 patients with DCM and to compare these variables with echocardiographic data. The results are as follows : 1) DCM showed diffuse systolic and diastolic dysfunction of LV. The systolic impairment is accounted for the diastolic impairment in DCM. 2) The increased standard deviation of phase angle of left ventricle(LVSDph) revealed LV asynchronous contraction in DCM. 3) LVSDph showed significant correlations with other RVG parameters such as LV ejection fraction, and peak ejection rate, peak filling rate and also with LV systolic and diastolic diameter measured by echocardiography. It is concluded that LVSDph may be useful in evaluation of LV systolic and diastolic function in patients with DCM as well as LV asynchronous contraction.