PIP: Outbreaks of severe hemorrhagic fever with renal syndrome (HFRS) caused by Dobrava hantavirus (DOB) have been reported in Albania, Greece, and Bosnia-Herzegovina. A seroepidemiologic study conducted by the authors in Estonia provided the first evidence of human DOB infection in a Baltic country. Hantavirus infection was first confirmed in Estonia in 1986 and believed related to Puumala hantavirus (PUU). To enable precise serotyping, serum samples were collected from 1728 healthy people in 11 counties in Estonia. Of 51 samples confirmed as positive, 34 showed the highest reactivities to PUU, while 17 reacted best with DOB antigen. In a further analysis of 11 selected positive samples, six showed the presence of neutralizing antibodies specific to PUU and five reacted specifically with DOB. These findings suggest that both BOB and PUU cause human infections in Estonia.