The pathological features and experimental results of Minamata disease are summarized. This disease is an unusual neurological disorder resulting from eating a large amount of fish and shellfish of Minamata bay in Japan. Minamata disease is a toxic encephalopathy characterized by cerebellar atrophy of granule-cell type, preferential injury of both calcarine regions and degenerative disturbances, to a lesser degree, of other cortical areas. Other parts of the nervous system may occasionally be disturbed. There are little or no remarkable changes in organs other than the nervous system, except for an occasional fatty degeneration of the liver and kidney, erosion in the digestive tract, and hypoplasia of the bone marrow.