The aim of this study was to evaluate the evolution of lupus activity in end-stage renal disease (ESRD) patients due to lupus nephritis and to determine the long-term prognosis. We reviewed the clinical courses of 45 patients with ESRD due to systemic lupus erythematosus (SLE). We analyzed the course of SLE following the onset of ESRD, with special attention to the clinical and serological manifestations, survival time on dialysis, and renal transplantation outcome. Disease activity was measured using the SLE Disease Activity Index (SLEDAI). Of the 45 patients, 21 patients were being treated with hemodialysis (HD), 11 were undergoing peritoneal dialysis (PD), and 13 underwent transplantation. Duration of follow- up was 53 +/- 29 months. The SLEDAI score on commencement of renal replacement therapy was not significantly different among the 3 groups (HD: 4.2 +/- 4.2, PD: 4.3 +/- 2.3, Transplant: 3.2 +/- 1.9). However, disease activity scored by follow-up maximal SLEDAI during dialysis or transplantation showed a significant increase after peritoneal dialysis (HD: 5.0 +/- 3.6, PD: 7.4 +/- 3.7, Transplant: 2.2 +/- 1.7, p < 0.05). When the individual changes in the maximal SLEDAI score were considered, a significant increase was apparent after peritoneal dialysis (p < 0.05), but not after either hemodialysis or renal transplantation. There was no significant difference in cumulative survival rate, and also in technique or graft survival rates of the 3 groups. Among the variables tested, follow-up maximal SLEDAI score was the only significant factor associated with patient survival (odds ratio: 1.15, p < 0.05). The incidence (36% versus 19%) of high disease activity was greater, but not significantly, in the peritoneal dialysis group, as compared to the hemodialysis group. Clinical activity of SLE was apparent in 65% of patients in the first year of dialysis, but none showed any activity after the third year of dialysis. We found that although lupus disease activity declined after patients progressed to ESRD, lupus disease activity still affected patients' survival. An incremental increase in postdialysis lupus activity was not uncommon, especially during the first one year of dialysis. During the follow-up period, maximal SLEDAI score increased significantly after peritoneal dialysis. However, the long-term prognosis was not significantly different according to the treatment modality.