Social work literature about ACT is limited. As is typical of much of social work’s derivative knowledge base, the literature from the fields of psychology and social psychology contribute to understanding ACT and its application to social work practice. The literature on ACT dates back to the early 1980s but, more recently, has been evidencing empirical promise (Hayes, 2005).ACT is a unique psychotherapeutic approach based on relational frame theory (RFT). RFT questions the context in which rational change strategies exist based on principles of behavior analysis. By examining the interactions that people have with their natural and social environments (contexts), RFT provides an understanding of the power of verbal behavior and language. The theory holds that much of what we call psychopathology is the result of the human tendency to avoid negatively evaluated private events (what we think and feel). ACT highlights the ways that language traps clients into attempts to wage war against their internal lives. Clients learn to recontextualize and accept these private events, develop greater clarity about personal values, and commit to needed behavior change. For social workers, this philosophy is best understood as “person in environment,” with the added variable of how language is used to interpret and direct those environments.