Animal research provides evidence that sleep deprivation influences the dopamine system. Knowledge about the effect of sleep deprivation on motor performance in patients with Parkinsons disease is scarce. This study examines the influence of total and partial sleep deprivation compared to normal sleep on motor state and performance in Parkinson's disease. Fifteen nondepressed patients with Parkinson's disease underwent one night of total sleep deprivation (TSD), one night of partial sleep deprivation (PSD) after 3 a.m., and one control night of normal sleep (S), performed in a random, nonconsecutive order. Over a period of 3 hours the following morning, motor evaluations (United Parkinson's Disease Rating Scale, [UPDRS] and tapping rate) were performed before and every 30 minutes after intake of the usual morning dopaminergic drug dose. All patients underwent polysomnography apart from the sleep deprivation protocol. Mean UPDRS motor scores and tapping velocities did not differ significantly after each of the schedules, but a subgroup of four patients improved their motor score after partial sleep deprivation. These data do not confirm previous findings of an overall positive influence of sleep deprivation on motor function in Parkinson's disease. However, the results indicate that different response types to sleep deprivation may exist and that a subgroup of patients could benefit from partial sleep deprivation. © 2001 Movement Disorder Society.