Nephritis occurs in 20%-50% of children with Henoch-Schönlein purpura (HSP), and the onset of renal involvement may be delayed for weeks or months in a substantial proportion of patients. The present study was performed to determine whether corticosteroid therapy was effective in preventing delayed nephritis in children with HSP. The medical records of 69 children with HSP were reviewed. Nineteen patients had acute nephritis occurring from 1-12 days after the onset of other signs and symptoms. The remaining 50 patients had no evidence of acute renal involvement. Of these 50 patients, 20 were treated during the acute phase of the illness with corticosteroids, while 30 never received corticosteroid therapy. Delayed nephritis (> 3 weeks following an initial normal urinalysis) occurred in 4 of 20 (20%) patients who received prior corticosteroid treatment, and in 6 of 30 (20%) patients who were not treated. These results indicate that early corticosteroid therapy does not prevent delayed nephritis in children with HSP.