In 1998 - 2008, serum samples from 464 patients, predominantly residents of the Moravia-Silesian Region, were examined in the Department of Virology, Public Health Institute in Ostrava, using Enzyme-Linked ImmunoSorbent Assay (ELISA) for the detection of specific anti-hantavirus antibodies. Seropositivity was ascertained in 41 persons (8.8%). More patients tested seropositive against Hantaan virus (24, i.e. 58.5%) than against Puumala virus (13, i.e. 31.7%). Four persons were reactive against both antigens. Clinical symptoms corresponding to hantavirus infection were observed in 19 seropositive patients. Fifteen of them had antibodies reactive with Hantaan virus antigen (cross-reactive with anti-Dobrava virus), 3 patients had antibodies against Puumala virus and 1 patient had both types of antibodies. Clinical data on the other seropositive persons were lacking. The higher rate of Dobrava virus infections in the Moravian-Silesian Region seems to be associated, among others, with the geographic distribution of striped field mouse (Apodemus agrarius) which is the main reservoir of Dobrava virus in Central Europe.