A method is described for visualizing the three-dimensional structure of horseradish peroxidase-labelled neurons in the central nervous system of Xenopus laevis tadpoles. The reconstruction is simple, and performed on a commercially available image processing system. Minimal operational skill is required for using this method. Also, various improvements were made where user's simplicity (user-friendliness), speed and required computer memory are concerned. In addition, the excellent properties of the IBAS II system, such as image filtering and image editing functions are fully available, offering a fast, clean and complete final image reconstruction.