We report results on the seroprevalence of antibodies to Coxiella burnetii in cattle and healthy people in Korea. Upon agreement with dairy owners, serum samples from 414 dairy cattle were collected between March and June 2001 and samples from 205 people for health screening were collected between April and December 2002. The sera were analyzed for the presence of anti-C. burnetii phase II antibodies using an indirect microimmunofluorescence test; strong fluorescence at a 1:32 dilution was regarded as positive. The overall seroprevalence of C. burnetii in cattle in Korea was 25.6%, with regional variation from 8.9 to 59.3%. Of the positive serum samples, 75.5% had antibody titers >or=1:256. By contrast, only 1.5% of people in a rural area were seropositive, and most of the positive samples had low antibody titers. In conclusion, this study showed that relatively high seropositivity of C. burnetii in dairy cattle, accordingly, the studies on the high-risk groups are needed to evaluate the seroprevalence for this organism in Korea.