Hantaviruses belong to the group of "emerging" viruses. Pathogenic European hantaviruses can cause a human disease designated "hemorrhagic fever with renal syndrome" of varying severity. In general, diagnostics of hantavirus infections are based on immunofluorescence assays using virus-infected cells or enzyme immunoassays and Western blot tests using recombinant nucleocapsid proteins. For highly sensitive detection of hantavirus-specific antibodies in the enzyme immunoassay, a homologous hantavirus nucleocapsid protein is needed as a diagnostic antigen. Serological typing of hantavirus infections can be obtained by neutralization assays, which in certain cases require the use of late convalescent sera. The seroprevalence in the normal German population is about 1%. In professionally exposed risk groups, e. g., forest workers, a seroprevalence higher than that in the normal population was observed. Endemic regions for hantavirus infections are located mainly in Baden-Württemberg. In the years 2001-2003 an annual number of about 200 clinically apparent hantavirus infections were registered in Germany. Neutralization assays detected almost exclusively human infections caused by Puumala and Dobrava viruses, only very rarely by Tula virus. Until this day in Germany mainly mild to moderate courses of human hantavirus infections have been documented. Besides infections caused by "German" hantaviruses, up to 10% of the clinically apparent hantavirus infections registered annually in Germany are caused by infections imported from other countries, mainly from Europe. So far only very limited molecular genetic data about the circulating hantaviruses in Germany are available. Additional investigations are needed to get a more precise picture about the distribution of hantaviruses in Germany and to calculate the resulting risk for the human population.