Objectives: Research has demonstrated that psychological therapies are not routinely delivered in acute mental health inpatient settings despite being recommended by the National Institute for Health and Care Excellence (NICE) guidelines. This study aimed to identify the barriers and facilitators to implementing psychological therapies in acute mental health inpatient settings.Methods: A systematic review and narrative synthesis was undertaken. Primary studies were included if they examined the implementation of a NICE recommended psychological therapy in acute psychiatric inpatient settings and were of any study design. Four databases were searched for eligible studies (MEDLINE, CINAHL Plus, PsycINFO and Embase) and Google Scholar.Results: A total of 16 studies (a mixture of both qualitative and quantitative methodologies) were included in the review, and the majority evaluated the implementation of Cognitive Behaviour Therapy. Overall, the literature was deemed to be of poor to moderate quality. The main barriers to the implementation of psychological therapy were the busy nature of the ward, multi-disciplinary professionals not being suitability trained and the acute nature of service users mental health difficulties. Facilitators to implementation included the adaptation of interventions to be specifically delivered in the acute inpatient setting, training of multi-disciplinary professionals, leadership support with the delivery of psychological therapies and prioritising the therapeutic relationship.Conclusions: There is a requirement for senior management to prioritise the implementation of psychological therapies and update clinical guidelines to describe modifications necessary to implement psychological therapies in acute inpatient settings.Future research should improve their methodological quality and continue to develop the evidence base of brief psychological therapies in acute inpatient settings.