This paper estimates the causal effect of permanently migrating as a child from a rural area to an urban area on human capital outcomes. The authors utilize a recent survey of urban-rural 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. It was found that childhood migration to urban areas increase education attainment by about 4.5 years by the time these individuals are adults. In addition, the childhood migrants face a lower probability to be underweight by about 15 percentage points as adults. However, there is no statistically significant effect on height, which is a measure of long-term nutritional intake, and we only find a weak effect on the probability to be obese. Therefore, the results suggest a permanent, positive, and large effect of childhood migration on education attainment and some health measures. In addition, the results can rule out any negative effect on health.