Evidence has been growing that the pathogenesis of lymphoproliferative disease involves immune processes deregulation. It is believed that antigens or immunological elements can trigger transformation of normal lymphocyte polyclonal population into monoclonal neoplastic disorder--lymphoproliferative disease. Extensive studies point to the link between malignant lymphoma development and autoimmune or inflammatory diseases--namely rheumatoid arthritis, Sjörgen's syndrome, coeliac disease, systemic lupus erythematosus or thyroiditis. Increased risk of lymphoproliferative disease development was also proved for some infections. These infections involve both viral (e.g. Epstein-Barr virus, HIV or hepatitis C virus) and bacterial agents (e.g. Helicobacter pylori, Borrelia burgdorferi). Besides various lymphomas, the links to autoimmune/inflammatory diseases have also been described in chronic lymphocytic leukaemia. Regarding clinical medicine, it is necessary to distinguish patients with autoimmune, inflammatory and infectious diseases who are at the increased risk of tumour development. New approaches must be found to lower this risk. Also, the relationship between autoimmune/inflammatory disease therapy and lymphoma development should be clarified. Although lymphomas associated with autoimmune and inflammatory diseases represent only a small proportion of all lymphomas, any new findings regarding these diseases can cast light on lymphoma pathogenesis as a whole.