In 2011 a serologic screening for treponemal infections in 181 free-living European brown hares (Lepus europaeus) from three populations (north and south Germany, eastern Austria) was performed. The screening was carried out using an indirect immunofluorescence test (IFAT). None of the animals showed clinical signs. Nonetheless, the seroprevalence was 63.8%, 42.8% and 43.9% for the Austrian, southern and northern German populations. Only four sub-adult animals showed a positive reaction. In the two German populations, adult female hares were affected significantly more often than sub-adults and males.