Six patients with Kawasaki disease (KD) were treated with prednisolone (1 to 2 mg/kg/day) for 3 days (from days 10 to 12 after the onset of the illness) after apparently unsuccessful treatment with intravenous immunoglobulin (IVIG, 2 g/kg/dose and additional 1 g/kg/dose). Five patients responded immediately to the first course of prednisolone infusion. One patient failed to respond to the first course of prednisolone therapy, but he did respond to the second 3-day course of therapy. None of the patients demonstrated a further progression of coronary artery dilatation or any adverse effects. Standard-dose and short-term corticosteroid therapy therefore appears to be a safe and effective treatment for patients with IVIG-resistant KD.