OBJECTIVE: To assess the predictors of attrition from a clinical pediatric obesity treatment program. METHODS: We evaluated 2- through 20-year-old patients first seen at the Duke University Healthy Lifestyles Program between October 2006 and December 2008. We assessed the predictors of early dropout (not returning for any follow-up visits within 1 year) and of noncompletion (not attending at least 6 visits within 1 year after entry). RESULTS: The sample included 983 patients. In adjusted analyses, non-white non-Hispanic children were more likely to be early dropouts than white non-Hispanic children (odds ratio [OR] = 1.46, 95% confidence interval [CI] = 1.03-2.07). Non-white non-Hispanic children were more likely to be noncompleters than white non-Hispanic (OR = 1.56, 95% CI = 1.03-2.36) and Hispanic children (OR = 2.56, 95% CI = 1.34-4.90). CONCLUSIONS: Race/ethnicity predicted patient attrition. Investigation into this association and program modification are needed to reduce attrition in certain racial/ethnic groups.