The importance of consumers in planning, providing and evaluating mental health services has received increasing recognition. Consumer participation as staff members on professional multidisciplinary teams describes one model of consumer involvement in providing services. This report gives the perspective of the professional leadership of such a team which employs two full-time "consumer advocates" (CAs). CAs have made significant and valuable contributions to the clinical work of the team by virtue of their street smarts, engagement skills, peer support, positive role modeling, fighting stigma, and education of co-workers. However, the CA/professional collaboration presented a number of challenging questions for ongoing discussion, including: 1) What is the role of the CA? 2) What are the boundaries between CAs and patients and the implications of these boundaries for the potential effectiveness of CAs? 3) What supervision should the CA have and with whom? 4) What is the impact of the CA's individual experience with mental illness on their work? Examples are presented of both the clinical contribution of CAs and how the importance of addressing the above questions became evident in the work of the team. We found that CAs were extremely important team members; however, an ongoing dialogue between consumers and professionals is essential to operationalize this important collaboration.