Outcomes research is a broad term. It involves not only investigations of the link between medical care and outcomes, but also activities aimed at assessing quality of care. The number of individuals and organizations involved in outcomes research has grown rapidly over the past decade. Despite this activity, some observers question whether outcomes research can deliver on its promises. In this paper, we define the scope of outcomes research and then discuss its potential for fulfilling the expectations of various stakeholders who have played a role in its design and implementation.