Cytokines play an important role in the pathogenesis of systemic lupus erythematosus (SLE) and lupus nephritis. This is currently a very active area of research. Of particular interest is the use of cytokines as biomarkers of disease activity in SLE and lupus nephritis. Can cytokine measurements assist in early detection of renal flare in known lupus nephritis? Can such measurements be used to distinguish between flare and chronic damage? Or help to confirm renal remission? Could they be used to help assess the required duration of immunosuppression and reduce the need for invasive renal biopsy? This review discusses limitations of current laboratory methods in monitoring SLE, how measurements of cytokines may contribute in relation to following disease activity and summarizes what is known about cytokines as biomarkers in SLE and lupus nephritis.