EBV infections were studied in paraffin embedded lymph node specimens (n = 20) on DNA, protein, and histological level. The lymph nodes were obtained from 20 patients all testing positive for EBV serologically. The EBV DNA was detected by non radioactive in-situ-hybridisation using the BamHI W fragment of the virus. The EBV latent membrane protein was detected immunohistochemically using the LMP antibody (DAKO). Infected cells were characterized by monoclonal B cell antibodies. By in-situ-hybridization we found positive signals for EBV in all specimens. In contrast, no LMP was detectable immunohistochemically in 2/20 lymph nodes.