Amyotrophic lateral sclerosis can be associated with profound sleep disturbances resulting from factors such as reduced mobility, muscle cramps, swallowing problems and anxiety. Although few studies have examined sleep patterns in ALS, disease-related symptoms such as restless legs and increased myoclonic activity can disturb both the initiation and maintenance of sleep. In addition, sleep-disordered breathing, exhibiting as hypoventilation, has been reported in patients with ALS. Interference with sleep patterns may produce daytime symptoms and activities of daily living can be further affected by an increased incidence of depression. Pharmacotherapy of sleep disturbance should be directed at the underlying cause and when hypnotics are required these should be short acting to minimise the carry-over effect into daytime.