This article investigates the relationship of early marriage to school participation and whether other factors, including individual or family characteristics and childbirth, moderate the relationship. It uses national household survey data for Eastern Africa, pooled at the regional level. Overall, findings confirm that marriage and schooling appear largely incompatible across the Eastern Africa region at present. The results of the main analysis indicate that married girls are roughly 31 percentage points less likely to be attending school than their unmarried peers. The effect of marriage on school participation trumps other observed factors, including childbirth. Based on an extended analysis using the timing of marriage and two consecutive years of education data in Malawi and Kenya, the article concludes that marriage is a predictor of subsequent school exit.