How social workers in managed mental health care settings exercise their professional authority may have profound consequences for the provision of ethical and value-based services to vulnerable populations. Building upon Gidden's theory of structuration, this article describes the use of critical ethnography as a specific research methodology that may support social workers in the exercise of their authority. This article examines the historical roots of critical ethnography and provides a detailed examination of its underlying assumptions and research procedures. The article concludes with a case example of a critical ethnography conducted within a managed mental health care setting.