So far, service users have not been systematically involved in social work theorizing. However, disabled peoples's movements, mental health service users/survivors and other service users have developed their own knowledges based on direct experience and they have generated their own conceptual frameworks and bodies of theory. There are fundamental problems in social work seeking to interpret service user knowledges. Their developments and interpretation require the direct involvement of service users and their organization in social work theorizing. There are strong practical, philosophical and political arguments for involving the knowledges and theories of service users and their organizations in the process of social work theory-building. This paper considers an inclusive approach to social work theorizing. While highlighting the importance of service users and their organizations being effectively included in social work theorizing, it also argues the need for them to have support and opportunities to develop their own prior and separate discussions about theory, including social work theory.