While optimal treatment strategies are widely established for daytime treatment of Parkinson's disease (PD), nighttime problems of PD are often not adequately addressed in clinical practice. Nocturnal/sleep disturbance is common in PD and occurs due to a combination of the disease process and effect of dopaminergic and other treatments. The role of dopamine and other neuropeptides such as hypocretin is being investigated in the causation of sleep problems in PD. The impact of sleep dysfunction in PD on daytime fatigue and sleepiness is also being explored as such issues have important implications. The recently described Parkinson's disease sleep scale aims to measure the causes of sleep dysfunction in PD in a semi-quantitative manner and using this scale we have shown that sustained dopaminergic stimulation initiated at bedtime may help with improving motor symptoms at night and secondarily improve sleep and daytime functioning in PD.