This article uses survey data from the German Socio-Economic Panel (GSOEP) to analyze the persistence of educational attainment across three generations in Germany. I obtain evidence of a robust effect of grandparents' education on respondents' own educational attainment in West Germany, net of parental class, education, occupational status, family income, parents' relationship history, and family size. I also test whether the grandparent effect results from resource compensation or cumulative advantage and find empirical support for both mechanisms. In comparison, the intergenerational association between grandparents' and respondents' education is considerably weaker in East Germany and is also mediated completely by parental education. There are hardly any gender differences in the role of grandparents for respondents' educational attainment, except for the fact that resource compensation is found to be exclusively relevant for women's attainment in both West Germany and in East Germany after German reunification and the associated transition to an open educational system.