Certain cancers occur more frequently in systemic lupus erythematosus (SLE) as compared with the general population, as recent data substantiates. The risk appears to be most heightened for lymphoma. Several pathogenic mechanisms may explain these observations, although little is definitively known. One particular concern relates to whether cancer risk in SLE is increased by medication exposures. Cooperative efforts to evaluate this have been undertaken by the Systemic Lupus International Collaborating Clinics and the Canadian Network for Improved Outcomes in Systemic Lupus research groups. This and other works in progress will, it is hoped, considerably advance the knowledge regarding the association between autoimmune diseases and malignancy.