Vitamin A supplementation reduces morbidity, mortality, and blindness among children in developing countries. The objective of this study is to characterize the coverage of the Cambodian national vitamin A program among preschool children and to identify risk factors for not receiving vitamin A supplementation. The study subjects were preschool children and their families who participated in the 2005 Cambodian Demographic and Health Survey (CDHS), a nationally representative survey. Of 1,547 preschool children, aged 12-59 months, 42.8% received a vitamin A capsule within the last six months. There were no significant differences in paternal education, child age, fever within the last 2 weeks, stunting, underweight, or wasting between children who did or did not receive a vitamin A capsule. Maternal education of =10 years (Odds Ratio [OR] 2.09, 95% Confidence Interval [CI] 1.02 – 4.29), 7-9 years (OR 1.46, 95% CI 0.99 – 2.15), 4-6 years (OR 1.71, 95% CI 1.26 – 2.32), and 1-3 years (OR 1.50, 95% CI 1.10 – 2.06) was associated with the child receiving a vitamin A capsule compared to no formal education in multivariate analyses adjusting for other potential confounders. The national vitamin A supplementation program in Cambodia did not reach over one-half of preschool children in 2005. Greater maternal formal education appears to be an important determinant for receipt of a vitamin A capsule by preschool children.