Guidelines for the management of suicidal behaviour have been produced in many countries but there is little evidence regarding their utility and effectiveness. There is also a dearth of research to inform implementation. This presentation will focus on multiple NICE guidelines in England produced over two decades – three for self-harm and one for suicide prevention. The specific objectives will be to: 1) review key elements of the guidance 2) examine evidence for positive or negative impacts 3) consider research and practice on the factors facilitating or hindering implementation of guidelines 4) discuss how guidelines might best be implemented in the future The content of the NICE clinical guidelines for self –harm from 2004, 2011, and 2022 and the NICE public health guidelines for suicide prevention will be reviewed. Evidence for their effectiveness will be investigated using new and unpublished national and local data. Quantitative and qualitative research on guideline implementation, with specific reference to suicidal behaviour will be reviewed. The author’s real-world experience with guideline implementation will also be presented. Finally, strategies to ensure that future guidelines are read, disseminated, and implemented will be discussed.