Abstract Within the European Commission-funded MEDIGRID project, Grid computing technology is used to integrate various natural hazard models and data sets, maintained independently at different centres in Europe, into a single system, accessible to users over the internet. Each centre forms a process (application) or data storage node and has been fitted with the Globus toolkit, which provides the distributed computing environment functionality that is required for the system set up. In addition, several Grid data management components were developed to allow the system to operate on different computing platforms. Access to the data and application management services is enabled through a Grid Portal. A series of portlets enable users to access the system, providing a personalised interface to the Grid. Integration of the individual models required them to be modified as web services, so as to be run remotely over the internet. As the models have different data characteristics, a common data format was adopted for creating harmonised data sets and allowing the exchange of data between the models. As an example, the Fire Spread Engine model is used to derive a map of areas that have been burnt by fire. This forms an input to the SHETRAN hydrology, soil erosion and landslide model, which in turn could provide data for other models such as vegetation regeneration. The use of the system is demonstrated for a site in south-west Spain where a large forest fire occurred on 2 August 2003. The MEDIGRID system marks an advance in the integration of independently constructed models to provide improved hazard assessment technology.