During the past 20 years, the application of scanning electron microscopy (SEM) to nematological investigations has considerably increased our knowledge about the structural features of nematodes. However, two relatively new techniques, namely three-dimensional visualization of specimens (stereopsis) and taking quantitative measurements from three-dimensional images (stereometry) offer additional insight. This investigation demonstrates how these techniques can be utilized and applied to studies in nematology. Stereopsis of nematodes is easily attained with a standard SEM by tilting the specimen 4 to 8° between two successive micrographs. The resulting micrographs, which constitute a stereo pair, contain parallax information that is needed for stereopsis. Three-dimensional visualization of the pair is achieved by an individual using a simple stereo viewer or by an audience when a Polaroid projection system is employed. The three-dimensional images that result improve resolution and clarify the shapes, topography and spatial relationships of structural features. Quantitative information, which is not attainable from a single two-dimensional micrograph, can be obtained from a stereo image by using a four-minor stereoscope equipped with a parallax measuring system. Information obtainable with this instrument allows one to make simple, accurate measurements, contour maps and models of specimens. The application of these two techniques, which are used in conjunction with SEM, are potentially important to morphological, anatomical, and taxonomic studies of nematodes as well as to their interactions with host tissues and naturally occurring pathogens.