Greatly improved diagnosis and investigation of fetal central nervous system abnormalities is the result of impressive technologic advances in ultrasonographic imaging. This applies as well to the study of spinal and facial abnormalities that are associated with central nervous system anomalies. More attention has been paid to midbrain structural defects, such as agenesis of the corpus callosum and abnormalities of the cerebellum, with the introduction of three- and four- dimensional ultrasound. Notwithstanding all these recent rapid technologic advances, many professionals --- except for a few pioneers --- have difficulty keeping up-to-date. The purpose of this review of basic principles and various applications of three-dimensional ultrasound to the fetal central nervous system evaluation is to inform professionals working in obstetric ultrasound of those advances. We will focus primarily on normal findings of three-dimensional sonography of the fetal central nervous system. We will also discuss a range of topics from methods of real-time scanning and software manipulation to the application of these techniques to each section of the fetal nervous system.