A new method for preparing ferruginous (asbestos) bodies for electron-optical examination is described. Pulmonary tissue is dissolved in bleach and the residue collected on a Millipore® filter. The ferruginous bodies are localized by light microscopy, and a portion of the filter containing a body is cut out and mounted on a coated electron microscope grid. The filter is dissolved in acetone vapor in a condensation washer, leaving the bodies, as well as uncoated submicroscopic fibers, on the grid. This method can be used to obtain bodies from the lungs of individuals after all degrees of asbestos exposure, but it is particularly useful when dealing with minimally exposed or non-exposed individuals whose lungs contain very few bodies. The procedure allows easy identification of body cores by electron diffraction or electron microprobe analysis.