In an investigation of about 1,000 workers in these mines, individual cases of a mild Parkinson's disease were discovered as well as lighter forms of encephalopathy. In a group of workers, manifestations of functional disturbance of the nervous system were discovered combined with single microorganic symptoms of injury of the central nervous system. This leads to the assumption that they suffer from the initial stage of chronic manganese intoxication. Prolonged observation will be required to arrive at a final solution for the question of the etiology of these changes. The results of the observation indicate that it is necessary to carry out measures to improve the medico-sanitary services and to assure healthier working conditions for the workers in the Chiatura manganese mines. Such measures are being taken at the present time.