The co-production of knowledge by diverse stakeholders, including experts, researchers, and service users, is becoming of increasing interest in mental health care. The paper highlights potential ethical dilemmas that arise in research involving service users as co-producers of knowledge. Prior to the research study, issues of tokenism, the dual role of health care researchers as researchers, and inclusivity in recruiting service users as co-researchers may arise as ethical dilemmas. During the research, service user co-researchers who have experienced coercion may be at risk of being retraumatized. There may be difficulties with authorship in academic publications and presentations at conferences. The issue of full payment of service user co-researchers could also be problematic. After the research study has ended, there may be an ethical dilemma on how to end the relationship created because of the research collaboration without causing harm.