After a short review of the functional aspects of electrical stimulation in rehabilitating paralysed patients, the article describes its effects on spasticity. Three different studies are briefly described. In the first one paraplegic patients' knee extensors and flexors were stimulated with four channel stimulator. In the second one two channel stimulation was applied to the ankle joint flexors and extensors in hemiplegic patients, while in the third, the effects of spinal cord stimulation were studied in multiple sclerosis patients. Although the parameters and sites of stimulation were different in each study, the effects were similar. In approximately 50% of paraplegic and hemiplegic patients stimulation caused decrease of reflex activity which lasted more than half an hour. In M.S. patients measurements were performed only in intervals of day and therefore short term effects were not documented. Two days after interruption of continuous spinal cord stimulation the reflex activity significantly increased in the majority of patients. In addition to this increase the volitional force decreased considerably.