Although the pathogenesis of Hodgkin's disease is not clear, molecular analyses reveal characteristic features. EBV infection can be demonstrated in more than 50% of cases at the DNA or protein level. Recently, immunoglobulin gene rearrangements were found in single Hodgkin and Reed-Sternberg cells. Sequence analyses revealed that the rearranged Ig genes have frequently somatic mutations, which indicate that the cells are derived from the germinal center. These rearrangements may be used as defined markers to detect residual disease after chemotherapy. Modern polychemotherapy regimen and radiotherapy are very effective, and 60-90% of patients, depending on stage of the disease and risk factors, can be cured. Salvage therapy for relapsed patients including high-dose chemotherapy with autologous stem cell support frequently results in remission although duration is frequently short. New immunotherapy strategies with immunotoxins or bispecific antibodies are currently analysed in clinical studies.