SummaryThe brains of two autopsy cases from long term mercury mine workers were studied histopathologically, histochemically and by electron microscopy and neutron activating analysis Histopathologically, any specific changes were not observed.The mercury in the brains showed a high concentration; high in the cerebral cortex and the substantia nigra, low in the spinal cord and in the cauda equina. By histo‐chemical analysis, small granules of mercury were seen scattered in the cytoplasm of nerve cells, in particular in the Purkinje cells. Electron microscopy revealed electron dense granules in the cytoplasm of Purkinje cells which were assumed to correspond to mercury granules.Jt was concluded that the nervous tissue in the case of chronic inorganic mercury poisoning keeps high concentration of mercury over a long period whereas morphophysiological normally is well retaine