This study investigates the extent to which national educational policy factors can explain differences in the probability of students repeating a grade in primary and lower-secondary education across OECD member countries. Data from the PISA 2009 study, the OECD "Education at a Glance" brochures, and the TALIS 2007 study were analyzed by means of three-level logistic regression models. The results indicate that a remarkable amount of variation in the likelihood of student grade retention lies at the country level. National educational policy factors, however, only partly explain this variation, indicating that traditions and societal beliefs regarding the benefits of grade retention also play a role in the explanation for international differences in retention. (Contains 2 figures, 4 tables, and 14 footnotes.)