In 2004, the American College of Physicians joined with the National Library of Medicine in an effort to help patients find reliable health information free of commercial bias at the Web site MedlinePlus.gov. The aim of this study was to evaluate the usefulness of the MedlinePlus.gov site as perceived by patients who were referred to the site by their internist. Materials and Methods: A 27-item questionnaire developed by the American College of Physicians Foundation was distributed between January and May 2005 to a convenience sample of 893 adult patient volunteers attending 34 internal medicine practices across the United States. Results: The questionnaire revealed that although most patients (55%) routinely look up medical information, only 43% had used MedlinePlus.gov. Of those who had used the site, 95% were satisfied with the information they found there, and 94% said the information they found at MedlinePlus.gov would help them make better health decisions. Discussion: Patients who used the MedlinePlus.gov site at the recommendation of their physician found it easy to use, informative, and felt it would help them make better health decisions. Directing patients to this high quality, noncommercial, educational resource online may be an important adjunct to patient education efforts by physicians. © 2008 by The American Federation for Medical Research.