Impairment of nervous functions has been investigated by clinical and neurophysiological methods in 55 workers exposed to inorganic mercury intoxication and 27 controls living in the same area. A polyneuropathy, mainly of sensory type, has been found in 6 exposed workers (10,9%) and 2 control (7,4%); a mono or multineuropathy of sensory or motor type was present in 15 exposed (27%) and 10 control (29,6%) subjects. Central N.S. involvement has been found in 7 out of 12 exposed workers examined and in 1 out of 7 controls by electronystagmography. Neurological examination demonstrated minor signs of cerebellar type in 3 instances.