Dobutamine (DOB) stress radionuclide ventriculography (RVG) is proposed for evaluating left ventricular performance in patients with Kawasaki disease (KD). Dobutamine stress RVG, up to 15 microg x kg(-1) x min(-1), was performed in 40 patients with a history of KD, some of whom had a perfusion defect (PD group) on dipyridamole stress thallium-201 myocardial imaging, some of whom had no perfusion defects (NPD group), and some of whom had no coronary artery lesions (C group). No significant differences in either systolic or diastolic indices of the left ventricle at rest were observed between the 3 groups. Although hemodynamic responses were similar in all patients after DOB stress, early diastolic index of the first third filling fraction decreased only in the PD group and was significantly lower in this group compared with the C group (p<0.01). The asynchrony index increased significantly in those patients with coronary stenosis after DOB stress (p<0.05). No serious side-effects were observed during the study. Even late after onset, patients with myocardial ischemia as a result of KD still had impaired early diastolic filling and asynchronous relaxation of the left ventricle. As an alternative to exercise testing, DOB stress RVG is a safe and promising means for serially evaluating left ventricular performance in patients with KD.