Serum samples from 380 cattle were analysed for the presence of bovine immunodeficiency-virus (BIV) antibodies by focus immunoassay (cell-ELISA) and immunofluorescence assay (IFA). All specimens originated from dairy farms in the eastern part of Germany, which had been randomly collected during the period 1989-1991. The cattle were clinically healthy and free of bovine leukaemia virus (BLV) and bovine-virus diarrhoea-virus (BVDV) antibodies. Infection of cell lines with BIV was monitored by syncytia formation, cell-ELISA, and immunofluorescence. The seroprevalence of BIV antibodies was 6.6%, as determined by cell-ELISA. Comparison of IFA and cell-ELISA showed that all IFA positive sera were also positive in cell-ELISA. However, additional sera were reactive only in cell-ELISA. This first report suggests that BIV infection may cause minor problems in German cattle, while BIV is present in a similar prevalence to that reported from other countries.