A survey of the frequency of hepatitis B markers in 258 subjects from Kavango, northern South West Africa/Namibia, was undertaken during February - May 1983. The hepatitis B surface antigen and hepatitis B e antigen carrier rates were 13,6% and 2,7% respectively. Only 1,9% of the subjects were negative for all the markers tested, indicating that infection had been present at some stage in 98,1% of the sample. No known transmission method of the virus seems to fit this high exposure rate. The possibility that arthropod transmission of the virus may play a role in the epidemiology of the disease in Kavango is being investigated. All subjects tested for antibodies to hepatitis A virus were found to give a positive result. Of the arboviruses tested for, West Nile virus was usually predominant and was probably responsible for most of the arbovirus infections. Antibodies to the Sindbis, Chikungunya, Germiston and Rift Valley fever viruses were also found.