Suicides by mental health patients account for around a quarter of all suicides (Walby et al, 2018). Within services a range of approaches have been developed and implemented to reduce the risk of patient suicides. After every patient death by suicide, a review is carried out to identify recommendations which may assist in preventing future suicides. It is therefore important to identify the most effective methods for implementing these recommendations. The objective of this systematic review, completed in Northern Ireland, was to identify how recommendations from Serious Adverse Incident (SAI) reviews can be effectively implemented to contribute to reducing deaths by suicide within mental health services. Eleven electronic databases were searched for relevant work from 1 January 2005-30 November 2020. Quantitative, qualitative and mixed methods studies were included. A narrative synthesis was carried out of published and unpublished work on the effectiveness of implementing recommendations, after a death by suicide in mental health services. The review, which includes 41 published papers and reports, found that the literature is focused on producing recommendations to reduce future risk of suicide in mental health services. There is a lack of focus on the extent and effectiveness of the implementation of these. Recommendations have often not been tested or operationalised, limiting the translational value of these contributions. Leadership and culture are also identified as key drivers for change in mental health services. This review demonstrates that high quality research is being complete in this area, however, the majority of published research presents recommendations from reviews of mental health patient suicides. There is a lack of research focusing on implementing recommendations and evaluation of implementation, once recommendations have been made.