Background: Consumers United for Evidence-based Healthcare (CUE) is a coalition of consumer advocacy groups working in collaboration with the US Cochrane Center. CUE sought to increase knowledge about evidencebased health care (EBHC) and enhance advocacy effectiveness by developing Understanding EBHC, a free online course for consumer advocates (see www.cochrane.us). Objectives: To describe and assess experience with Understanding EBHC. Methods: Over several years, we developed and tested Version 1.0 of Understanding EBHC. The course comprises 5.5 hours of audio lectures with slides, presented in six modules, viewable in 10–15 minute segments. Hosted by the Johns Hopkins Bloomberg School of Public Health, the course has a single lecturer (MM). Evaluations, integrated into the course development process, were conducted through in-person workshops and via electronic feedback. Results: The course launched 15 September 2007. As of 5 March 2008, 469 persons had enrolled and 225 (49.3%) had completed Module 1. Of those completing Module 1, 90 (40%) had completed all 6 modules. Almost one quarter (102/469) of the participants were from outside the US, representing 30 countries. Participant self-reports indicated that 80% of the 359 completing the baseline survey were female, 70% Caucasian, 85% had a university degree, and half were employed full time. Before starting the course, 68% reported that their reason for taking the course was personal growth and development. Almost 30% were ‘‘not so confident’’ and 60% were ‘‘moderately confident’’ about their knowledge of EBHC. Almost half reported that they or their organization worked on issues related to EBHC, yet 35% reported low confidence in explaining The Cochrane Collaboration, and 25% reported low confidence in describing how to use The Cochrane Library. Post-course, with 98 responding, a majority expressed confidence in both topics. Feedback has been positive, with clarity, organization, use of examples, and the ability to repeat sections particularly noted. One CUE advocacy group has required completion of Understanding EBHC as a prerequisite to enrollment in one of their courses. Updated course assessments will be presented at the Colloquium. Conclusions: Understanding EBHC has enrolled well and feedback is positive.