We report herein an infant case of Ebstein's anomaly with abnormal diastolic filling pattern of the left ventricle. We also compare the case with a comparable case without such abnormal filling pattern. The patient, who had pulmonary valve stenosis, patent ductus arteriosus and mild mitral regurgitation, underwent transventricular valvotomy at 30 days of age. Postoperative course was uneventful. Serial Doppler echocardiographic studies were performed at 2 hr, 40 days, and 52 days of age. Peak velocity and flow velocity-time integral of early diastole, and ratios of the peak velocities and velocity time integrals of the early diastole and atrial contraction were below the 95% confidence limits of the normal controls. Our case suggests that left ventricular diastolic dysfunction may exist in the Ebstein's anomaly when it is associated with mitral valve abnormality such as mitral regurgitation.