Functional electrical stimulation of the extremities (FES) is a new method for the rehabilitation of paralysed paretic patients. Small, electronic stimulators are worn by the patient, who can voluntarily control the electrical currents applied to his paralysed muscle. These currents activate the disabled extremities and make them at least partially functional once more. This paper presents a short history of FES and discusses recent advances and problems in the field. A detailed account of present work with single- and multi-channel stimulation of paralysed legs is given, as well as some research data on upper extremity stimulation.