[영문]Discussions about user involvement in the mental health services tend to throw up four major areas of concern: the capacity of service users to participate, their lack of participation skills, the need for a positive organisational culture and the need for arenas of participation. This article presents evidence from participatory action research with Irish mental health service users which explored how they could more equally participate in advisory committees. Participants identified barriers to their equal participation due to unequal cultural, physical, mental and economic resources, time, power, 'stigma'(prejudice) and lack of respect for their experiential knowledge and emotional expression. These barriers fall within the 'equality of condition framework' developed by Baker and colleagues. Enabling equal user involvement in strategic decision-making requires more than arenas of participation - it requires comprehensively addressing service users' structural disadvantages throughout the process of involvement.