A 42-year-old female with IgA monoclonal gammopathy and Bence-Jones proteinuria suffered from recurrent episodes of Henoch-Schönlein syndrome and renal failure. The renal biopsy showed a diffuse proliferative ‘crescentic’ glomerulonephritis with mesangial IgA deposition. She responded to steroids but immunosuppressive therapy failed to prevent relapse. Since the introduction of cytotoxic therapy she has had no further relapse. Cytotoxic therapy may be beneficial in monoclonal gammopathy even in the absence of malignancy where the clinical syndrome is the result of the presence of a parapro