A system to evaluate and follow morphologic changes in number, size, shape and other histological measurements of transverse myelinated fiber profiles in nerves and fiber tracts has proven to be a useful analysis tool. Applications of the system include the enumeration and sizing of peripheral nerves and central nervous system tracts for the morphologic study of development, aging, regeneration, neurotoxicity, pathologic conditions, also, the morphometric assessment of intra-epidermal nerve fiber densities, IENFD. The primary aim of the system is to provide both an operator-interactive and automated method for the detection, sizing and measurement of myelinated fibers. The system, Imaging System for Nerve Morphometry, was shown, to provide the specific functionality required to perform morphometric studies of peripheral nerve, compared to commercial systems which perform a more general estimate of histological features. The system consists of the tissue preparation process, a video camera-ready microscope capable of various resolutions, and a computer system for image acquisition, data analysis, data display and statistical analysis. The morphometric measurements obtained from this system have been used for quality control by clinical nerve pathologists, in the study of human peripheral neuropathies and the clinical assessment of IENFDs. In assessment of test retest reproducibility of periodically-sampled nerves, high degrees of reproducibility were achieved for most morphometric measurements.