The case is reported of an adult male patient, who, in the course of prolonged use of excessive doses of ergotamine given by the intravenous route, developed a severe condition characterized by profound mental confusion and tonic and clonic spasms, and terminating rapidly in death. Post mortem, there was the characteristic picture of acute Schilder's disease. The possible relation of the ergotamine intoxication to the demyelinating process is taken into consideration and briefly discussed.Abstract Teaser