The mechanisms involved in the reproduction of educational inequalities are not yet fully understood, and therefore, this study aims to go beyond the scope of postnatal mechanisms. This study examines the role of prenatal exposures in the reproduction of educational differences. It is argued that health behaviors during pregnancy are associated with levels of maternal education and that prenatal exposures affect educational attainment. Thus, prenatal exposures might contribute to our understanding of educational inequalities. Using data from the German Health Interview and Examination Survey for Children and Adolescents (N=5,670), evidence is found that the risk of lower educational attainment is increased in offspring exposed to tobacco, or to both alcohol and tobacco, during pregnancy. Additionally, prenatal exposures mediate the effect of maternal educational level on offspring’s school attainment. These results emphasize the need to include prenatal exposures when conducting research on both social origins and educational attainment.