This article provides an overview of the prevalence, cause and treatment of insomnia in common neurological diseases (restless legs syndrome, stroke, multiple sclerosis, Parkinson´s disease and Alzheimer´s disease) with an additional focus on the bidirectional relationship between sleep and neurological disorders.Insomnia is prevalent, but frequently unrecognized in the context of neurological diseases. Although it is widely known that sleep has a relevant impact on quality of life in general and cerebral function in particular, sleep disorders receive little attention in the prevention and treatment of neurological diseases.