Bipolar disorder is a severe and chronic disorder, ranked in the top 10 leading causes of disability worldwide. While there have been important advances in treatments, a significant proportion of patients continue to experience disabling symptoms between episodes and the risk of relapse into an episode of depression or mania remains high. Three lines of evidence suggest that sleep disturbances are strongly coupled with interepisode dysfunction and symptom worsening in bipolar disorder: (1) sleep disturbance is a core symptom of bipolar disorder, (2) experimental studies suggest that sleep deprivation can trigger manic relapse and (3) there is evidence that sleep deprivation can adversely affect emotion regulation the following day. The clinical management of the sleep disturbances experienced by bipolar patients, including insomnia and hypersomnia, may include medication approaches, psychological interventions, light therapies and sleep deprivation. The advantages of the psychological interventions include that they are low in side effects, may be preferred by patients, are durable and have no abuse potential. There is a critical need to develop and test specific interventions for the sleep problems experienced by patients with bipolar disorder.