Clinical practice guidelines offer potentially valuable tools for rationalizing health care delivery and improving patient outcomes. Currently, major efforts are under way to develop, test, and refine guidelines for a wide variety of medical conditions and procedures. Although methods for producing guidelines are fairly well understood and continue to improve, experience suggests that guidelines rarely translate directly into changes in practice. For various reasons, including physician resistance or incomplete understanding of the need for guidelines, they have proven difficult to implement. This article describes a broad range of strategies for implementing clinical practice guidelines based on the social influences that affect health practitioner behavior. The article also examines issues surrounding the selection and use of individual strategies or combinations of strategies in specific efforts to improve the quality of health care.