Our previous effort at reconstructive morphology included the marriage of the horseradish peroxidase (HRP) neurohistochemical method to a Lucite plate reconstruction technique. Limitations imposed by this combination of methods has led us to develop a computer-based system that utilizes image-processing techniques and the data obtained from HRP-processed serial light microscope sections. Labeled neurons of the baboon abducens nucleus were identified by HRP conjugated to wheat ger agglutinin. Using the resulting serial sections and a unique imaging process involving a pattern recognition algorithm, our computer-based system automatically differentiates neuronal from nonneuronal features, delineates the surface boundaries of the neuronal population, and then assembles these serial sections into a solid three-dimensional structure that can be rotated and further analyzed. A computer-generated solid model of this neuronal population has been reconstructed and reproduced in a two-dimensional publishable format. It is anticipated that with further development this system will be able to utilize data from the same specimen to study spatial relations through three-dimensional reconstruction, as well as to study the quantitative morphology of a neuronal population. Other computer-aided systems are noted, as are the advantages and shortcomings of the present method.