Little information is available about the clinical status and outcome of patients with a long history of lupus nephritis. We have reviewed the dossiers of 25 patients (23 women and two men) who have been monitored by our Unit for more than 10 years after the diagnosis of lupus nephritis. At presentation the mean age was 28.5 +/- 10.33 (SD) years, the mean plasma creatinine was 136.1 +/- 144.7 (SD) nmol/l, the mean proteinuria was 3.02 +/- 2.7 (SD) g/day. At initial renal biopsy 18 patients showed diffuse proliferative glomerulonephritis, six patients showed membranous glomerulonephritis and one showed focal proliferative glomerulonephritis. All patients but one were treated with corticosteroids and 18 were also given immunosuppressive agents. At the last observation (16 +/- 4.6 (SD) years after presentation), 19 patients have normal plasma creatinine (11 of them show proteinuria less than 0.2 g/day) and six patients show increased plasma creatinine (mean 203.3 +/- 61.9 (SD) mmol/l). Eleven patients have been without any treatment for 88 +/- 64 (SD) months. The incidence of lupus flare-ups fell significantly after the tenth year (0.31/patient/year between 0 and 10 versus 0.11 between years 11 and 27; p = 0.01). No case of pericarditis or cerebritis occurred after the tenth year. Only one case of cerebral thrombosis occurred before the tenth year, but ten severe atherosclerotic cardiovascular and cerebrovascular complications were seen after the tenth year (two cardiac infarcts, three angina pectoris, four cerebral thrombosis, one cerebral haemorrhage). Two cases of cancer (thyroid and lung) occurred after the tenth year. The professional rehabilitation was good in most patients.(ABSTRACT TRUNCATED AT 250 WORDS)