KORA-gen is a resource for genetic epidemiological research, based on the KORA platform (Cooperative Health Research in the Region of Augsburg). Biosamples and phenotypic characteristics as well as environmental parameters of 18,000 adults from Augsburg and the surrounding counties are available. The age range of the participants was 25 to 74 years of recruitment and is 30 to 90 years in 2005. KORA-gen can be used by external partners. Interested parties can inform themselves interactively via internet about the available data and the rules of access. The genotypic data base is a common resource of all partners.