Lupus nephritis is a major cause of morbidity and mortality arising from systemic lupus erythematosus. The pathology seen on renal biopsy and clinical features of renal involvement remain major prognostic factors and therapeutic guides. Serologic markers also correlate with disease activity, but more significantly, the identification of cationic and anti-endothelial cell antibodies in patients may have pathogenetic implications. Experimental studies demonstrating pathogenic roles for cationic nuclear antigens, cationic and anti-idiotypic antibodies, and genetic control of antibody production, are being transferred to the clinic. Duplication of these results in patients suggests that similar mechanisms are operative in humans. Insights gained from pathological studies will lead to new therapeutic strategies, but at present lupus nephritis therapy is based on nonspecific immunosuppression. Therapeutic trials testing several established and new modalities have been published in the past year, but they are anecdotal and lacking in controls.