In a 62-year-old man with an 8-month course of sporadic classical amyotrophic lateral sclerosis, many Lewy body-like hyaline inclusions (LI) were observed in spinal anterior horn cells, hypoglossal nuclei, nucleus ambiguus, and motor nuclei of the trigeminal nerve. These motor neurons showed a mild degree of neuronal loss, several Bunina bodies, spheroids and chromatolytic neurons. Tract degeneration was limited to pyramidal tracts. In addition to intensely stained LI, immunoreactive skeins or granules were recognized by a polyclonal anti-ubiquitin antibody. Thick filaments of 15 to 20 nm in diameters with granules formed conglomerated masses with varying amounts of neurofilaments in the anterior horns, corresponding to light microscopically observed LI. More commonly, these thick granulofilamentous profiles were dispersed in small bundles or individually in the cytoplasm. Electron microscopically, there was no close association of filaments with Bunina bodies.