Using panel data from Madagascar, we study how birth order influences the transition into adulthood. We find that earlier borns drop school at a younger age, attain less schooling, and thus have lower cognitive skills than later borns. They also start working out of the family firm earlier and girls marry younger. The precocious transition of the firstborn is likely to finance younger siblings’ education. These mechanisms are stronger in rural areas, where the liquidity constraints are stronger. Results are robust to different specifications commonly used in the birth order literature and are not sensitive to the presence of fostered children in the household.