Sixteen adult patients with Schönlein-Henoch nephritis, selected by strict inclusion criteria, were studied retrospectively. At the time of discovery of the nephropathy, 11 patients had normal plasma creatinine and 5 other patients had renal insufficiency. All patients had renal biopsies, which were studied by both light and immunofluorescence microscopy. After a mean follow-up of 90.5 +/- 59.1 months (range 16-261), 3 patients were in chronic dialysis (18.7%), 8 other patients had renal function deterioration (50%), with creatinine clearance ranging from 31 to 60 ml/min. Four other patients had mild urinary abnormalities with normal plasma creatinine (25%) and only 1 patient was in complete clinical remission (6%). No clinical features at onset were predictive for the clinical outcome of the disease, while in the biopsies the percentage of crescents was higher in patients who developed renal insufficiency. High IgA serum levels were correlated (p = 0.0242) with a favorable course. It is concluded that Schönlein-Henoch nephritis of the adult carries a high long-term risk of renal dysfunction.