Objective: We investigated the perception of dental hygienists regarding their adequacy of providing diabetics with diabetes-related oral health preventive education. Methods: A one-page questionnaire printed on both sides was mailed to 2,237 licensed registered dental hygienists with a South Carolina (SC) mailing address. In addition to the dental hygienists' background and practice characteristics, their perception of adequacy for educating patients with diabetes on various diabetes-related oral health topics and reasons for inadequate coverage of materials were queried in the survey. Results: After two follow-up mailings, 995 completed and usable surveys were returned. An average of 93.6 percent of respondents indicated that they adequately covered topics of oral hygiene and general oral health issues. However, about 60 percent of respondents reported not covering all essential materials related to oral health when educating diabetic patients. The three most common reasons were: a) insufficient time (60.1 percent); b) patient disinterest (41.2 percent); and c) insufficient information on oral care and diabetes (39.7 percent). Respondents reporting insufficient information were less likely to adequately address the effect of periodontal disease on diabetes (P < 0.001), effect of uncontrolled diabetes on periodontal disease (P < 0.001), and dry mouth management (P = 0.03). Conclusion: This study indicates that SC dental hygienists do not routinely provide patient education on diabetes-related oral health and healthy lifestyle topics. Lack of time, patient disinterest, and insufficient information were the three main reasons for respondents not covering these essentials. A practical method for improving dental hygienists' comprehensive service to patients with diabetes is to offer them more continuing education on diabetes and oral health to supplement their knowledge, skills, and confidence to educate this growing population. © 2008, American Association of Public Health Dentistry.