A group of forty-nine hemiparetic patients with limited emotional, communication and sensibility involvement and with recent lesion of cerebrovascular aetiology was randomly divided into two groups of twenty-four and twenty-five subjects. Both groups received traditional physiotherapy treatment for one hour/day, one group received twenty min/day of peroneal nerve stimulation. The maximum voluntary dorsal flexion moments of the ankle joint of the affected and non affected extremities were measured with an isometric brace twice a week for one month and for both groups. The recovery of moment in the stimulated group turned out to be about three times greater than in the control group and considerably less dependent upon age, time from lesion, initial value, side of lesion. Three patients using a peroneal brace at home as an assisting device were again evaluated two months later and a further improvement was observed. This work gives statistical support to previous observations based on very few cases and provides a statistically reliable answer concerning the entity of FES induced recovery of muscle force in hemiparetic subjects.