To analyze the long-term outcome in patients with silent lupus nephritis, we retrospectively studied 20 patients with systemic lupus erythematosus without clinical renal involvement who had renal biopsies in our unit between 1978 and 1986 and reviewed 193 cases reported between 1957 and 1995. Two patients of the current series were lost to follow-up. Mean follow-up in the other 18 was 13 +/- 3 years (range, 2 to 17). On kidney biopsy, nine had class I, six class II, one class IV, and two class V disease (WHO classification). Three patients with prior normal renal function died of nonrenal causes. During the study, the remaining 15 patients had normal renal function and urinalysis. Most patients from the literature had "mild" histologic lesions, but 30 had diffuse proliferative glomerulonephritis. Over an average of 46 months of follow-up from biopsy, renal survival rate and patient survival rate were 98% and 91%, respectively. Three patients died of end-stage renal failure. In conclusion, end-stage renal failure in patients with silent lupus nephritis is rare regardless of the histopathological renal lesions. Patients survival depends on nonrenal causes.