Theory and research have not kept pace with the growing interest in evaluating quality of mental health care, resulting in the use of unvalidated quality indicators. A framework for validating quality indicators is offered by which quality is viewed as the relationship between service structures, processes, and outcomes. Adoption of this framework will facilitate the measurement of quality using valid indicators and should be useful to agencies in their continuous quality improvement efforts. Valid information about the quality of mental health care services will help purchasers and consumers make more informed health care decisions.