This article reviews the associations of cancer with rheumatic diseases. Recent epidemiologic data linking the autoimmune connective tissue diseases with malignancy will be emphasized. Reports linking the occurrence of malignancy with rheumatoid arthritis, systemic lupus erythematosus, idiopathic inflammatory myopathy, scleroderma, and vasculitis are described. The effect of immunomodulating drugs in the development of malignancy is discussed. Mechanisms potentially responsible for malignant transformation in the lymphoproliferation of Sjogren's syndrome are described. The relationship of gout to cancer as well as direct effects of cancer on the musculoskeletal system is also reviewed.