The importance of enabling a wide range of people to participate in reserach and evaluation reflects continuing calls for service users to be a part of the decision-making which goes on around them. Involving service users in project work is not without its challenges, raising pertinent ethical and practical issues which need to be considered and reflexively responded to. In this paper we will provide a summary of the key ethical and governance issues to consider when undertaking (primarily) qualitative research with those deemed 'vulnerable', before offering an outline of some of the best practice approaches to applying these issues in the field