Pulsed Doppler echocardiography was used in conjunction with real-time two-dimensional and M-mode ultrasound techniques in 9 fetuses between 28 and 40 weeks of gestation. Of these, nine also had echocardiographic examination performed neonatally. In one fetus with complete heart block, pulsed Doppler echocardiography showed tricuspid regurgitation. The ventricular and atrial rates were accurately determined by M-mode ultrasound; pericardial effusion was noted in the two-dimensional examination. The left ventricular stroke volume, as measured by the Doppler technique, was 13.5 ml, and the minute output was 486 ml/min. In another fetus, Doppler studies assisted two-dimensional echocardiography in detecting pulmonary aneurysm. Neonatal echocardiography confirmed this and also showed the presence of tetralogy of Fallot. In three fetuses with ventricular ectopy, 30% to 50% reduction in the right ventricular stroke volume was recorded by the Doppler technique. This study demonstrates the clinical potential of pulsed Doppler echocardiography in assessing fetal cardiac disorders and justifies further investigation to define its clinical utility. © 1985.