Many patients are treated in intensive care units daily, often over a long period of time. Sleep plays a role that should not be underestimated for these patients. Sleep disorders are a relevant problem for intensive care patients and lead to a higher prevalence of delirium in these patients and thus to a longer length of stay in the intensive care unit and to a higher mortality. This article tries to show the causes of sleep disorders in intensive care medicine and possible strategies for avoiding sleep disorders in intensive care patients.