The outcomes of 32 lupus patients with rapidly progressive crescentic glomerulonephritis were studied. Lupus nephritis accounted for 51.6% (32/62) of all patients with biopsy proven rapidly progressive crescentic glomerulonephritis during a six year observation period that includes 961 consecutive native kidney biopsies. Median entry serum creatinine was 221 micromol/l. All patients received induction therapy with pulse methylprednisolone (n =27) or intravenous cyclophosphamide (n = 5). Maintenance therapies included prednisolone alone (group 1), prednisolone plus intermittent pulse intravenous cyclophosphamide (IVCY) (group 2) and prednisolone plus daily oral cytotoxic drugs (group 3). Twelve patients eventually had uremia. Seven further patients died of infection during therapy. One patient still had renal insufficiency and twelve patients had favorable clinical outcome (serum creatinine < 200 micromol/l). Patients in group 3 were more likely to have favorable clinical outcome than group 2 (P = 0.01; Fisher's exact test). Survival analysis found that the three year survival of 'group 2' was 27.6% while that of 'group 3' was 83.3%. Our results suggest that lupus nephritis is not an infrequent cause of crescentic glomerulonephritis. Therapy with IVCY is not necessary associated with good outcome. Selected patients can be effectively treated with daily oral cytotoxic drugs as a reasonable alternative therapy.