OBJECTIVE: Populations with the lowest literacy and health literacy in the U.S. are also among those disproportionately burdened by diabetes and its complications. Yet, suitability of publicly available diabetes and cardiovascular (CVD) patient education materials for these patients is not clear. We evaluated selected American Diabetes Association (ADA) and American Heart Association (AHA) print education materials for accessibility and usability characteristics. RESEARCH DESIGN AND METHODS: English-language, print patient education brochures addressing lifestyle/behavioral management of diabetes and CVD were obtained from the ADA (n = 21) and the AHA (n = 19). Materials were evaluated using 32 criteria, 23 addressing literacy demand and 9 addressing behavioral activation, compiled from authoritative sources on development of low-literacy consumer health information. RESULTS: Of the 32 criteria identified by two or more sources, ADA materials consistently met 11 (34%) and AHA materials consistently met 8 (25%). Criteria most frequently achieved were text case, use of cues (e.g., bullets) to emphasize key points, design of graphics/illustrations, some provision of "how to" information, and positive depiction of cultural images. The least consistently achieved criteria were reading grade, word usage (e.g., scientific jargon), sentence length, font size, line length, white space, visual organization, limited scope, clear and specific (e.g., step-by-step) behavioral recommendations, and demonstration of audience relevance and cultural appropriateness. CONCLUSIONS: Materials consistently met few criteria for usability by patients with low literacy, limited prior medical knowledge, and/or limited resource availability. Use of available criteria and methods for increasing reach of print education materials to these underserved patient populations is indicated.