Of eight acute infections in German tourists caused by sandfly fever virus, serotype Toscana (TOS). and diagnosed clinically and serologically, seven were acquired during visits to Tuscany, Italy, and one to Coimbra, Portugal. An indirect immunofluorescence assay (IFA) using infected cells, and a newly developed enzyme-immunoassay (EIA) using crude virus antigen prepared from infected Vero-E6 cells was used to detect anti-TOS IgM and IgG. In a seroepidemiological survey of 859 health care workers and medical students, anti-TOS IgG was detected in 1·0% by IFA, and in 0·7% by EIA. In 2034 German patients hospitalized for various diseases, 1·6% were positive for anti-TOS IgG by IFA, and 0·8% by EIA. Anti-TOS IgG was detected in 43 samples of commercial immunoglobulins at titres of 10–1000 by EIA. Although the seroprevalence of antibodies to TOS is low in Germany, TOS infection should be considered in patients returning from endemic areas who complain of fever, and headaches, and have symptoms of meningitis.