Our aim was to report the effect of two treatment regimens in 43 cases of severe Henoch-Schönlein nephritis (HSN) and immunoglobulin A nephritis (IgAN) (24 HSN, 19 IgAN). Group A, 11 HSN and 7 IgAN, 88% with an International Study of Kidney Disease in Children (ISKDC) biopsy grade > or = III and severe clinical features, were treated with corticosteroids, cyclophosphamide (CYC-P) and angiotensin-converting enzyme inhibitor/angiotensin receptor blocker (ACEi/ARB). Group B, 12 HSN and 13 IgAN, 72% with biopsy findings as above and 52% with severe clinical features, were treated with ACEi/ARB +/- corticosteroids. The outcome classification was: (a) healthy; (b) mild proteinuria, normal glomerular filtration rate (GFR); (c) active renal disease; (d) chronic renal failure. Twenty-six patients had a good outcome (a + b). The 17 children with poor outcome (c + d) had lower GFR at onset and at follow-up, higher albumin excretion at follow-up, and higher percentage of segmental glomerulosclerosis in the renal biopsy, than those with good outcome. Treatment with corticosteroids, CYC-P and ACEi/ARB was effective in increasing GFR, reducing proteinuria and decreasing the disease activity index. The proteinuria had decreased at follow-up in both groups. In group A, GFR increased and histopathological activity index declined after treatment. The outcome did not differ between groups A and B. The effects of treatment did not differ between HSN and IgAN.