Three dimensional (3D) reconstructions of brain anatomy and physiology have greatly improved our understanding of complex spatial and densitometric relationships. The complexity and sophistication of these imaging techniques has steadily improved in the last few years and there are many situations in which the static display of 3D models contains more information than can be easily appreciated. Animating a sequence of these displays adds another dimension to the visualization, understanding and communication of 3D data. This paper describes those situations that warrant animations, the techniques necessary to compute them and the results that can be obtained.