E-Government architectures started out as management instruments mainly focused on the technical (ICT); side of government. Today, they are developing into tools that map out the business side of government, and link this both to the governance and technology dimensions of government. There is a large consensus on the necessity of building «e-Government » on solid architectures, but no clear definition of what « e-Government architectures » are. The terms architecture, interoperability framework, reference architecture are often confused and used interchangeably. A Framework is rather a list of applications and tools. It provides e-Government interoperability by creating a pool of common tools. Architectures take it one step further by organizing these applications and not only listing them. "Interoperability means the ability of information and communication technology (ICT); systems and of the business processes they support to exchange data and to enable sharing of information and knowledge."1 It allows different channels to rely on a common infrastructure to complement each other. It also allows service delivery applications to be independent from the front-end delivery channels. The first part of this paper aims to discuss the various literature referring to e-Gov architectures. The second part looks at the institutional and technical environment by looking at some country case-studies around the world (UK, Germany, France, USA, Canada, Hong-Kong and Singapore);. The third part looks at the technical and political situation of the Latin American environment by looking at a four country-case study (Brazil, Chile, Colombia, Mexico);. Given the heterogeneous scenario on which countries in the region are currently developing their e-Gov architectures, the final part issues some recommendations by pointing out their main characteristics and thresholds to cross.