Results with real-time processable three-dimensional ultrasound (US) were assessed in 57 normal fetuses and two fetuses with hydramnios. Volume scanning time was 4 seconds, and a complete three-dimensional fetal image was displayed at the end of scanning. Although this method was limited in some respects, such as viewing direction, it was very useful when performed in conjunction with conventional tomographic US because of its speed and because some components were depicted more clearly.