It is highly desirable for health workers in the Aged care residential sector to be able to comply with contemporary best practice at the point of care, and meet all quality and reporting requirements with the support of one fully integrated information system. The provision of aged care consists of a complex and varied set of arrangements. All levels of Government, as well as consumers and the non-government sector, have some role in funding, administering or providing aged care for older Australians. This requires an Information Technology (I.T.) infrastructure that meets the needs of many stakeholders. The openEHR approach was designed to facilitate this approach. Hypothesis: Only with semantic interoperability is it possible to electronically transfer, share, exchange and meaningfully use all captured aged care information within decision support systems, to enable the mapping to an electronic knowledge base, regulatory reporting, undertake population surveillance, clinical practice evaluation and outcome analyses by entering data once only and enabling its use many times to meet multiple information needs at various locations. Objectives: This paper aims to raise awareness about the issues and research processes associated with the need to achieve semantic interoperability between information systems within the residential aged care sector. Our research aims to develop a process for capturing expert knowledge relevant to the aged care sector for the purpose of automating all data capture and enabling these data to be used to support clinical practice in accordance with aged care standards as well as to meet various reporting, management, research and planning requirements. A solution to these problems based on the use of openEHR archetypes will be explored in this project. Methods: an analysis of relevant documentation such as government requirements, clinical needs and clinical knowledge, together with an extensive literature review, including consultation and collaboration with many stakeholders to identify knowledge concepts for which a constraint model (archetype) needs to be developed, and following the development of these using the Archetype Editor as per the openEHR approach, test their accuracy via the conduct interviews and focus group discussions followed by a national Delphi study of aged care knowledge experts and subsequently placing them in a national repository. Expected results: This project has only just begun. It is a work in progress to demonstrate the value of semantic interoperability as only then will we be able to benefit fully from our Information and Communication Technologies (ICT) investments.