In addition to the meaning as Health Informatics Society of Australia, HISA is the acronym used for the new European Standard: Health Informatics - Service Architecture. This EN 12967 standard has been developed by CEN - the federation of 29 national standards bodies in Europe. This standard defines the essential elements of a Service Oriented Architecture and a methodology for localization particularly useful for large healthcare organizations. It is based on the Open Distributed Processing (ODP) framework from ISO 10746 and contains the following parts: Part 1: Enterprise viewpoint. Part 2: Information viewpoint. Part 3: Computational viewpoint. This standard is now also the starting point for the consideration for an International standard in ISO/TC 215. The basic principles with a set of health specific middleware services as a common platform for various applications for regional health information systems, or large integrated hospital information systems, are well established following a previous prestandard. Examples of large scale deployments in Sweden, Denmark and Italy are described.