There are many reasons for patients with idiopathic Parkinson's disease to develop sleep disorders and subsequent daytime sleepiness. Important causes are reduction of total sleep duration and sleep efficiency, and an increase in respiratory and motor arousals. This daytime sleepiness at first glance seems different from the “sleep attacks” which caused motot vehicle mishaps reported recently in persons taking pramipexole and ropinirole. There is, however, only little evidence that we deal with a new phenomenon in a new clinical situation, i. e. cataplexy-like attacks after high doses of new non-ergot dopamine-agonists. Until now there is no single case of a proven cataplexy on one hand, and older dopamine agonists like pergolide as well as L-Dopa + carbidopa have been reported to induce sudden onsets of sleep, too.