In Henoch-Schonlein purpura (HSP), involvement of the ileum and ascending colon with vasculitis can mimic appendicitis and cause unnecessary appendicectomy. A 13-year-old boy presented with signs of HSP and abdominal pain. He was treated with prednisolone (2 mg/kg/day) for 10 days, but there was no improvement. At laparotomy he had acute suppurative appendicitis. A 12-year-old girl presented with HSP associated with abdominal pain and bloody diarrhoea and at laparotomy was also found to have suppurative appendicitis. Both patients had vasculitic areas in the ileum. In HSP, although suppurative appendicitis is rare, it should always be considered and appropriate investigations, including ultrasonography, undertaken.