Medical ultrasound has during the last decades experienced enormous technological progress, and in obstetrics and gynaecology it has become an integral part of the clinical work. Within the last years several new ultrasound techniques have appeared. Three-dimensional ultrasound scanning (3DUS), in which there has been great interest, is one of them. Especially within obstetrics and gynaecology several papers on that topic describe promising results. Foetal diagnostics relying on morphological signs and accurate distance and volume measurements is one of the areas, believed to benefit from 3DUS. However, until now only few prospective works have been published, most of them counted as preliminary. Three-dimensional power Doppler can clearly depict the full three-dimensional continuum of early embryonic and umbilico-placental circulation. Fetal vascular anatomy that has been studied with three-dimensional ultrasound includes the umbilical cord, circle of Willis, aorta, renal arteries, and lung vessels. Recently, the 3D-PDU technique was employed for visualization of the fetal heart and vessels. The method enables the visualization of the main parts of the fetal vascular system under normal and pathological conditions. Thereby obstetrical and gynaecological ultrasound scanning will undoubtedly take another giant leap forward.