Beginning with its historical roots in the experimental animal laboratory, the token economy system of psychiatric treatment for adult patients is traced to its present state of development. Applications of operant conditioning to individual patients, ward-wide token economy programs, and studies comparing token economies with other types of psychiatric management both within ward and on an outcome basis are reviewed. Although token economic methods appear to be effective in increasing and maintaining selected target behaviors while patients are hospitalized, few attempts have been made to program contingencies in patients' natural environments following hospital discharges. Suggestions are offered with respect to extending the token economy into the home through the use of behavioral contracting or in intermediary settings (half-way houses) by continuing the operant environment. The empirical evaluation of these procedures is warranted. Moreover, there is an apparent need for a carefully controlled outcome study in which a token economy ward is compared with an “attention-placebo” group and a group undergoing an active form of psychiatric treatment such as “milieu” therapy.