We evaluated functional improvement in the upper limb of chronic (more than six months' duration) stroke patients who received one of two electrical stimulation treatments, conventional treatment, or no treatment. Twenty-two right-handed patients were assigned to one of four groups studied for 12 months posttreatment. Subjects received (1) EMG-initiated electrical stimulation of wrist extensors (EMG-stim), (2) low-intensity electrical stimulation of wrist extensors combined with voluntary contractions (B/B), (3) proprioceptive neuromuscular facilitation (PNF) exercises, or (4) no treatment. Subjects were treated for three months. Before treatment, upon completion of treatment, and three and nine months after treatment, subjects were evaluated by the Fugl-Meyer (FM) poststroke motor recovery test and by grip strength. Subjects also attempted three Jebsen-Taylor hand function tests and a finger tapping test at the same evaluation sessions, but many were unable to complete these tests. During the course of treatment, FM scores of subjects receiving PNF improved 18%, B/B improved 25%, and EMG-stim improved 42%. The aggregate FM improvement of the treated groups was significant from pretreatment to posttreatment, and the improvement was maintained at three-month and nine-month followups (all p less than .005). The treated subjects' improvement in grip strength was also maintained at both followups (p less than .10). In contrast, the control group showed no significant change in FM scores or grip strength. The four treated subjects who were able to perform the hand function tests and finger tapping at all four evaluations also improved on these tests.(ABSTRACT TRUNCATED AT 250 WORDS)