Nine adult patients, aged from 16 to 70 years, (mean 42 years), with Schönlein-Henoch syndrome were studied during the acute stage of their illness. Each presented with the typical purpuric skin rash, and renal disease was found in every case. Microscopic haematuria and proteinuria were consistently found and red cell casts were seen in urine from five patients. Kidney biopsy performed on nine patients showed focal glomerulonephritis in seven cases and diffuse proliferative nephritis in two. The finding of mesangial deposits of immunoglobulin A (IgA) in seven of eight patients is in agreement with recent reports suggesting that the syndrome is an immune complex disorder. The diffuse proliferative lesion was accompanied by loss of renal function, but there were no fatalities in this series. Corticosteroids administered during the acute stage appear to ameliorate the symptoms, especially the arthralgia and abdominal pain, and may prevent progression of the renal disease in some cases.