While a growing literature has analyzed the effects of parental migration on the educational outcomes of children left behind, this is the first study to highlight the importance of sibling interactions in such a context. Using panel data from the RUMiC Survey, we find that sibling influence on schooling performance is stronger among left- behind children. Hence, parental migration seems to trigger changes in the roles and effects among children. However, it is primarily older sisters who exhibit a positive influence on their younger siblings. We corroborate our results by performing a series of tests to mitigate endogeneity issues. The results from the analysis suggest that sibling effects in migrant households might be a mechanism to shape children's outcomes and success and that adjustments within the family left behind have the potential to generate benefits – or reduce hardship – in response to parental migration.