Objective The purpose of this study was to describe the use of three-dimensional power Doppler ultrasonography to identify vascular congenital anomalies of fetal portosystemic and umbilical venous systems. Study design In a prospective study, the hepatic and umbilical venous systems were examined in 390 fetuses with two-dimensional ultrasonography, color, and spectral Doppler imaging. Fetuses suspected to have anomalies of the portal system and ductus venosus were additionally examined with three-dimensional power Doppler ultrasonography. Results Vascular anomalies were identified in 8 fetuses (absent ductus venosus, n = 4; direct connection between the umbilical vein and the right atrium, n = 2; and direct connection between the umbilical vein and the inferior vena cava, n = 2) out of the 310 in which the venous system could be adequately imaged (prevalence = 2.6%). Three-dimensional power Doppler imaging showed the course of the umbilical vein, its relationship to the portosystemic circulation, and whether a ductus venosus was present. Conclusion Three-dimensional power Doppler ultrasonography can be used to image normal fetal hepatic and portal circulation, as well as identify anomalies of the fetal portosystemic and umbilical venous systems.