Sleep disturbances in patients with Parkinson's disease (PD) are common, are often severe, and are typically underrecognized and ineffectively treated. After the recognition that some patients with PD could fall asleep unexpectedly when driving, with resulting dangerous consequences, it became evident not only that PD medications might be partly responsible but that there were many additional factors contributing to sleep disturbance in these patients. This review discusses the myriad sleep disorders seen in patients with PD, presents their diagnostic features, and gives recommendations on their management. Effective management of sleep disturbances and excessive daytime sleepiness can greatly improve the quality of life for patients with PD.