The proliferation of research, particularly research into evidence-based care and quality improvement, has brought about a void in the need to educate, summarize, and distill scientific advances. Clinical policies or practice guidelines are a unique method of filling this void. While the number of policies published has increased significantly over the last 10 years, their impact on physician practice remains ill-defined. This article aims to provide historical background and methodology, explore physician attitudes toward them and their effectiveness at impacting clinical care, as well as discuss their future medical legal implications.