Pestivirus infection in domestic ruminants has been reported in several parts of southern Africa (Theodoridis and Boshoff, 1974). In'wildlife naturally occurring bovine viral diarrhoea virus (BVDV) infection has only rarely been reported (Plowright, 1969). It was the purpose of this investigation to record the antibody levels to BVDV in 535 sera from the following 9 Namibian wildlife species: roan antelope The sera originated either from wildlife cropping operations in southern Namibia or from the Etosha National Park in northern Namibia. Neither age nor sex of the sampled animals were known. All sera were stored at -20~ until testing.For the determination of antibody levels, a direct neutralising peroxidase-linked antibody (NPLA) assay using the 0712/Han/80 strain of BVDV was performed (Hyera et aL, 1987). Neutralising antibody titres greater than 1:5 were considered positive.The percentage of seropositive animals within a species, as well as the titre range, is given in Table I. Six out of 9 species were shown to have antibodies to BVDV. The prevalence in seropositive species ranged from 5 to 67 per cent. Giraffe and roan antelope sera showed titres 1 : 1,000; the highest antibody titres were found in 2 giraffe with 1:56,234 and 1:28,184. Oryx, kudu, sable antelope and blue wildebeest had titres of about 1:100 (Table I). All sera originating from red hartebeest, black wildebeest and springbok were free of detectable antibodies against BVDV.The data presented showed that BVDV infection is widespread in Namibian wildlife. Hamblin and Hedger (1979) demonstrated antibodies to BVDV in the sera of 17 out of 45 wildlife species from various African regions. Among these were sera from kudu, oryx, wildebeest, springbok and giraffe sampled in Namibia. In addition, we demonstrated antibodies in sera from roan and sable antelope but failed to detect antibodies in springbok sera.The very high antibody titres in giraffe and roan antelope suggest that these animals could have experienced a recent infection and that the BVDV strain which was used throughout the test is antigenetically similar to field virus strains which infected these animals. The isolation of a cytopathogenic pestivirus from a diseased giraffe in Kenya (Plowright, 1969) and the high titres measured in our survey indicate that giraffe are highly susceptible to pestivirus infection. No significance is attributed to the absence of antibodies in sera from red hartebeest and black wildebeest due to the low number of samples.Unless BVDV persistence and its perpetuation in wildlife species is proven, their role in the epidemiology of BVDV infection in livestock remains obscure.