OBJECTIVE The purpose of this study is to determine the association between personal characteristics, a person's oral health literacy, and failing to show for dental appointments at a university dental clinic. METHODS A secondary data analysis was conducted on data collected from 200 adults at a university dental clinic between January 2005 and December 2006. In the original study, an oral health literacy instrument, the Rapid Estimate of Adult Literacy in Medicine and Dentistry (REALM-D), was administered, sociodemographic and health information seeking behavior was gathered, and electronic records were reviewed. RESULTS Descriptive and bivariate analyses and a classification and regression tree (CART) analysis were conducted. Seeking health information through fewer sources vs. multiple sources was the strongest predictor of failing to show. The subjects' oral health literacy, as measured by the REALM-D List 3 score, was the next most significant variable. Classification and regression tree analyses also selected gender, chief complaint, age, and payment type as predictor variables. CONCLUSIONS Multiple factors contribute to failing to show for dental appointments. However, individuals who use fewer sources of oral health information, a subset of health literacy skills, are more likely to fail to show for dental appointments.