Background: Complementary and alternative medicine (CAM) is popular among U.S. health care consumers, but no study has examined how much health educators know about CAM. Purpose: To examine the knowledge of basic CAM concepts and common CAM therapies among health educators in the U.S. Methods: An online survey was conducted among 1,299 health educators with valid e-mails on a professional listserv. The response rate was 39%. The 16-item CAM knowledge scale yielded a Cronbach's alpha of .71. Results: Participating health educators were most knowledgeable about chiropractic and massage therapy, familiar with the general definition of CAM, understood whether acupuncture is beneficial in treating a variety of health conditions, and whether there is sufficient scientific evidence regarding CAM safety and effectiveness. Participants were unclear about the difference between complementary medicine and alternative medicine. CAM knowledge appeared to be influenced by the participants' sex, education level, race/ethnicity, and employment setting. Discussion: Similar to other studies, participating health educators were more familiar with the concepts of commonly used CAM therapies than those of less widely practiced ones. Translation to Health Education Practice: CAM education should be implemented as part of a professional preparation curriculum and in the form of continuing education for health educators in the U.S.