This article presents a guide to implement open data in Public Agencies (PAs). The guide is the result of a worldwide proposal’s study, of the application of a maturity model to diagnose the situation of PAs in Latin American countries, the opinion of experts in different excellence centers, e-government authorities, and developers of open data application in the world. The guide is simple and orients decision makers so that PAs following the actions of the guide can see their capacities improved when facing a diagnosis of their institutional maturity in implementation of open data.