The management of sleep disturbances in patients with dementia is a complicated and enormously important clinical and societal problem. In this review, we present one approach to the diagnosis and management of such sleep disturbances. Most disturbances can be categorized into four primary symptoms: insomnia, hypersomnia, excessive nocturnal motor activity, and hallucinations or behavioral problems. We describe how each symptom may relate to the dementing illnesses themselves, which primary sleep disorders may be at play, which medications employed for dementia may impact on the symptom, the role of depression in that symptom, and how circadian dysrhythmias can underlie that symptom. Although few well-designed studies have been conducted, we present management strategies for several sleep disturbances based on the literature and our clinical experience. Considering the impact on patient and caregiver quality of life, and the potential for delaying institutionalization with appropriate therapy, further research is clearly warranted to optimize the diagnosis and management of sleep disturbances in the cognitively impaired elderly population.