DNA-binding antibodies are produced during the course of many parasitic infections, including malaria, leprosy and schistosomiasis. These antibodies are also present in certain autoimmune diseases, such as systemic lupus erythematosus, and much information is available about their properties and contribution to related disease processes Here, Anne Wozencraft and Norman Staines consider how DNA-binding antibodies might arise during parasitic infection and discuss how an increased knowledge of their properties and functions could lead to a greater understanding of mechanisms of immuno-pathology in these diseases.