The design and implementation of Clinical Information System architecture is presented. This architecture has been developed and implemented based on components following a streng underlying conceptual and technological model. Common Object Request Broker and n-tier technology featuring centralised and departmental clinical information Systems as the back-end store for all clinical data are used. Servers located in the “middle” tier apply the clinical (business) model and application rules. The main characteristics are the focus on modelling and reuse of both data and business logic. Scalability as well as adaptability to constantly changing requirements via component driven Computing are the main reasons for that approach.