Decentralization is meant to improve access to public services, but relatively few studies examine this question empirically. We explore the effects of decentralization on access to health and education in Colombia using an original database covering over 95 % of Colombian municipalities. We show that decentralization improved enrollment rates in public schools and access of the poor to public health services. In both sectors, improving access was driven by the financial contributions of local governments. Small increases in own-shares of spending led to surprisingly large increases in the access of the poor in both sectors. Our theoretical model implies that where local information dominates productive efficiency, elected local governments will provide services better tailored to local needs. Decentralizing such services should increase their use by the public. Together, theory and empirics imply that decentralization made the Colombian state more accountable. It provided local officials with the information and incentives they need to allocate resources in a manner responsive to voters’ needs and improve the impact of public expenditures. Copyright Springer Science+Business Media New York 2014