We studied a patient with amyotrophic lateral sclerosis and the Klüver-Bucy syndrome. At autopsy there was extensive degeneration of the limbic system with the brunt of the changes in the medial temporal lobe, especially the entorhinal cortex and subiculum. Degenerative changes were also seen in the substantia nigra and lower motor neurons. Morphometric and biochemical studies implied a disease process that affected small, possibly somatostatinergic, cortical neurons. These latter findings and the lobar distribution of cortical atrophy were consistent with Pick's disease, but Pick bodies and ballooned neurons were not present.