The present study was designed to quantitatively evaluate fetal cardiac dysfunction in fetal congestive heart failure associated with cardiogenic hydrops fetalis. Thirty-seven cases of non-immunological hydrops fetalis and/or fetal heart disease were assigned to four groups: (1) hydrops fetalis with structural heart disease; (2) hydrops fetalis without heart disease; (3) structural heart diseases without hydrops, and (4) complete A-V block without hydrops. One hundred and ten control fetuses were also studied. The ejection fraction in the first and third groups was significantly lower than that in the control. In the first group, systolic flow velocity in the descending aorta normalized but gestational age was significantly lower than that in the controls. Compensation of fetal cardiac function in the fourth group (complete A-V block) was noted on the basis of higher flow velocity and higher contractility. The cardiothoracic area ratios of the pathological and control groups were also evaluated.