SUMMARY: SIMBioMS is a web based open source software system for managing data and information in biomedical studies. It provides a solution for the collection, storage, management and retrieval of information about research subjects and biomedical samples, as well as experimental data obtained using a range of high throughput technologies, including gene expression, genotyping, proteomics and metabonomics. The system can easily be customised and has proven to be successful in several large scale multi-site collaborative projects. It is compatible with emerging functional genomics data standards and provides data import and export in accepted standard formats. Protocols for transferring data to durable archives at the European Bioinformatics Institute have been implemented. AVAILABILITY: The source code, documentation, and initialization scripts are available at http://simbioms.org. CONTACT: support\@simbioms.org.