As parto fa ne valuation of serviceu sers'a nd carers'e xperienceo fi nvolvement in mental healthe ducation, training and research,a ne xtended literaturer evieww as undertaken. The purposeo ft hisw as to reviewp olicy underpinning serviceu sera nd careri nvolvement in thosea reas,i dentifyt he extent and range of involvement, the processesi nvolved, andt he extent to which the effectivenessa nd impacto fi nvolvement had been evaluated. The reviewf ound that therew as ar angeo fd ifferent ways in which peoplew erei nvolved. It identified different types and levels of involvement and different motivationsf or takingp art in involvement activities. Government policy and guidanceo np ublic and patient involvement (PPI)i nh ealth services has clearly been ad rivera nd has resulted in widespread involvement activityb ut thish as developed on an ad hoca nd inconsistent basis.Therea re benefits for serviceu sers and carers,t he NHS, and educational establishments arisingout of involvement activity. Theseinclude improvementsinthe health and well-being of serviceu sers,e nhancingt he student experience, and improvements to serviced elivery. However,t herea re stillb arrierst oi nvolvement including organisational factorsa nd unintentional discrimination. Payment for involvement activityremains an under researched area. Service usersv alue payments but welfareb enefits rules, and inconsistent interpretation of good practice guidance,m ean thisc an be af urther barrier to involvement. Currently, the evidenceb asee valuatingt he effectiveness of serviceu seri nvolvement in a range of activities including serviceplanning, delivery, education and research is limited.