Physicians and other health care providers rarely have the time to practice evidence-based medicine through the consistent application of the best available published evidence to answer clinical problems, or to explore questions that often arise in the context of treating a patient. Lack of time is often compounded by a lack of retrieval skills and knowledge of the structure of the published evidence. To bridge this evidence-practice gap, a 2000 editorial in the Annals of Internal Medicine proposed a new kind of health professional capable of bridging two vastly different environments by possessing clinical knowledge as well as skills in information retrieval and synthesis. The evolution of this important and multifaceted concept is provided through this article which is based on an invited presentation for the IFLA/Health and Biosciences Libraries Section sponsored session at the 2006 World Library and Information Congress: 72nd IFLA General Conference and Council meeting in Seoul, Korea