Twenty-eight children ranging in age from 1-6 years (11 girls, 17 boys) with Kawasaki disease and, for comparison, 30 normal children ranging in age from 1-8 years (8 girls, 22 boys) without any cardiovascular disease were included in this study. The left ventricular functions of the children were evaluated by equilibrium multigated blood pooling ventriculography (EMBPV), which was performed after in vivo labeling of red blood cells using 10 mCi Tc-99m pertechnetate. Scintigraphy was performed using a digital gamma camera with the aid of an electrocardiogram gate. The left ventricular functions were determined by Fourier analysis of the time-activity curve in the left ventricles. The parameters of the left ventricular functions included: 1) systolic phase--[a] ejection fraction (EF), [b] ejection time (ET), [c] peak ejection rate (PER), and [d] first 1/3 ejection rate mean (1/3ERM), and 2) diastolic phase--[a] peak filling rate (PFR), [b] fast filling fraction (FFF), [c] time to peak filling rate (TPFR), and [d] first 1/3 filling rate mean (1/3FRM). The results showed that no significant differences existed between the two groups in any parameter of the left ventricular function. The authors suggest that the left ventricular functions in children with Kawasaki disease are not apparently impaired. The results were proven by the presentation of the EMBPV in this study.