The authors evaluated the effects of pramipexole, a dopaminergic D2-D3 receptor agonist, on eight patients with idiopathic REM sleep behavior disorder. Five patients reported a sustained reduction in the frequency or intensity of sleep motor behaviors, which was confirmed by video recording, although no change was observed for the percentage of phasic EMG activity during REM sleep. Surprisingly, a decrease in the percentage of time spent with REM sleep muscle atonia was observed with treatment. The treatment did not modify the indexes of periodic leg movements.