We investigated the efficacy of plaque removal after an oral self-care demonstration among adult Gullah-speaking African Americans with diabetes. Fifty- four adults with diabetes completed an observed, uninstructed oral self-care demonstration with their normal mode of oral self-care. Before and after the oral self-care demonstration, the plaque levels of six test teeth were assessed using the Plaque Index. The mean percentage of plaque removal after the oral self-care demonstration was 27.4%. The mandibular teeth and the lingual surface had less plaque removal compared with the maxillary teeth and buccal surfaces. Only approximately 10% of participants achieved 50% or more plaque removal after the oral self-care demonstration. Thus, the majority of the participants did not achieve an acceptable level of plaque removal. Dental health professionals should emphasize better oral home care for people with diabetes and teach them how to access the lingual surfaces, especially of the mandibular teeth. © 2009 Special Care Dentistry Association and Wiley Periodicals, Inc.