The aim of this paper is to evaluate the effectiveness of high-intensity versus low-intensity transcutaneous electrical nerve stimulation (TENS) and versus placebo for treatment of hemiplegic shoulder pain. Three groups of 20 patients each (A, B, C) were studied. In group A high-intensity TENS was delivered at 3 times the sensory threshold with frequency of 100 Hz; in group B low-intensity TENS was delivered at the sensory threshold with frequency of 100 Hz. Group C received placebo stimulation. The treatment protocol consisted of 12 sessions (4 weeks). Before treatment, at the end of it and one month after, passive range of motion (PROM) for flexion, extension, abduction and external rotation were evaluated. Statistically significant improvements of PROMs were recorded for group A, but not for groups B or C.