Background: Around a third of the general population experience insomnia at some point in their lives. A lack of good quality sleep can negatively impact upon daytime functioning, relationships and behaviour. Although the issues and management of prisoner's mental health has been assessed thoroughly across the prison literature, the importance of poor sleep prevalence, associated causes and its management has failed to be systematically examined. My systematic integrative review of the sleep-prison literature collated and synthesized the evidence, informing the overall study objectives and design.Aim: The overarching aim of this mixed-methods thesis was to produce a treatment pathway to help manage insomnia in a prison population, acceptable to both staff and prisoners.Study 1: A national survey and telephone interviews examining current insomnia management practice in England and Wales prisons . Eight-four prisons took part (73%). The most common interventions were medication and sleep hygiene education. Analysis of telephone interviews revealed four main themes, insomnia as a normal occurrence in prison; the problem of medication in prison; the negative impact of the prison environment; and effective management of insomnia in prison.Study 2: A cross-sectional study looking at prevalence and associated factors of insomnia in male and female prisons was conducted. Two hundred and thirty seven prisoners completed a questionnaire battery. Around two-thirds had insomnia disorder and clinical, environmental and situational factors were much more likely in this group than those without insomnia.Study 3: Semi-structured interviews were conducted with staff and prisoners to explore perspectives of insomnia management. Three themes were found: value of good sleep, barriers and considerations for good sleep management and future direction of insomnia management in prison.Study 4: A modified Delphi consensus study was conducted with academic sleep researchers, prison staff and service users over three rounds of consultation. Consensus was achieved and a stepped-care treatment pathway was produced.Conclusion: When used in future practice, the treatment pathway should help practitioners to identify, assess and manage insomnia in a population that is twice as likely to experience insomnia as the general population.