Developing countries are experiencing unprecedented levels of urbanization. Although most of these movements are motivated by economic reasons, they could affect the human capital accumulation of the children who follow their parents to the cities. This paper estimates the effect of permanently migrating as a child from a rural area to an urban area on human capital outcomes in Indonesia. To our knowledge this is the first contribution in the Indonesian context. We utilize a recent survey of urbanrural migrants in Indonesia and merge it with a nationally representative survey to create a dataset that contains migrants in urban areas and non-migrants in rural areas who were born in the same rural districts. We then employ a measure of district-level propensity to migrate, calculated from the Indonesian intercensal survey, as an instrument. Our instrumental variables estimation shows that childhood migration to urban areas increased education attainment by around five years of schooling relative to an observably similar individual who remained in the rural area. In addition, the childhood migrants are healthier, shown through a lower probability to be undernourished without any higher probability to be obese. Therefore, our findings indicate the existence of a positive externality of migrating from rural to urban areas on the children of the migrants.