Abstract: Crisis and disaster management in the Netherlands has made huge leaps forward in recent years with regard to different organisations trying to manage one or more aspects of the safety chain. This research focuses on the information structure of health care during disasters with an aim to improve disaster management and tries to answer the following question: How can location based services improve information services within health care during disasters? Through the use of literature and interviews this thesis describes how disaster management can be improved through the use of Location Based Services (LBS). The scope of this research is aimed at better understanding the organisational processes during somatic health care. By defining a case and on the basis of literature and interviews in the Province of Utrecht, it was possible to develop a three layer graph model (3LGM). This model shows an overview of information processes performed by the health care organisation during the first hour after an accident. In this context, the 3LGM model is used to obtain an overview of the quality of information processing in such a problem area. The organisational structure, which deals with disaster management, consists of a strong co-operation between the police, fire departments, the local government and the 'Medical Aid during Accidents and Disasters' (GHOR). The size of the organisation depends largely upon the scale of the disaster, however the current information structure is not suitable for storing and processing the information in an efficient and effective manner. The same applies when displaying information related to casualties and safety within an area. With the help of location based services consisting of, geographical information systems (GIS), global positioning systems (GPS) and second or third generation telecommunication technologies, the existing information structure can be optimised. Expected advantages are higher accessibility to health care, a safer environment for rescuers, more time for managing the healthcare processes and an improved interdisciplinary co-operation between the police, fire departments, the local government and the GHOR. © Proceedings ISCRAM 2004.