Enterprise architecture is an active, strategic data basewhich defines a business, what us necessary to operate a business, including the technologies that are need to support its operations, and the transition processes necessary for implementing new technologies in reponse to changes in the needs of the business{1]. the strategic importance of enterprise architecture (EA) is recognised by a growing number of global enterprisesall over the world[2], [3] and investment in enterprise architectureprogammers raises the expectations of them being beneficial. in this context, the project "implementation ofanenterprise architecture proggammein five portuguese enterprises" aims too assess the way in which some portuguessenterprisesimplement or provide service to implement such a programme start-up, definition of the approach to the process, development and plan for transformation, use and maintenance. through case study methodology, using questionnaires and/or interviews, data from five eterprises were collected and implementation of EA in these enterprises.