To evaluate the efficacy of cyclosporin A (CyA) for treating severe Henoch-Schönlein nephritis (HSN), seven patients with nephrotic syndrome, aged 3.9-13.8 years (mean 6.5 years), were analyzed retrospectively. Mean follow-up times were 5.5 years (range 2-9 years). All underwent renal biopsy before treatment, and follow-up renal biopsy was performed in six of the seven patients. All patients improved, with 24-h protein declining from a mean of 9.2 g/m(2)/day (range 1.5-16 g/m(2)/day) to 0.3 g/m(2)/day (range 0.03-1.2 g/m(2)/day) (p=0.016) and serum albumin increasing from a mean of 2.1 g/dl (range 1.5-2.4 g/dl) to 4.6 g/dl (range 3.5-5.3 g/dl) (p=0.016) after CyA therapy. The activity index decreased significantly at the second renal biopsies obtained at a mean interval of 11.7 months after the first (6.4+/-3.3 vs 3.5+/-1.2, p=0.042, respectively), while the chronicity index and the tubulointerstitial scores did not change. On the immunofluorescent findings at the second biopsies, the degree of deposits of immunoglobulins such as IgA, IgM, C3, and fibrinogen decreased in five of the six patients. Although this case series is without controls, our study suggests that CyA may be beneficial to a subset of HSN patients with nephrotic syndrome.