Objectives: Corticosteroids are considered to be contraindicated during the acute phase of Kawasaki disease (KD) based on unfavorable results in early studies. In our hospital, however, corticosteroids have been used in some cases of KD with satisfactory results. We analyzed outcomes of patients with KD treated with or without corticosteroids. Study design: Medical records of 299 children with KD treated with one of the 4 regimens were reviewed retrospectively. Regimen 1 consisted of aspirin, dipyridamole, and propranolol; regimen 2 was regimen 1 plus prednisolone, 2 mg/kg/d, for 1 week, followed by tapering over 2 weeks; regimen 3 was regimen 1 plus intravenous γ-globulin (IVGG), 200 or 400 mg/kg/d, for 5 consecutive days; and regimen 4 was regimen 1 plus both prednisolone and IVGG. Results: Although patients treated with regimens 2 and 4 were more ill at presentation than those treated with regimens 1 and 3, respectively, the duration of fever was shorter in the former patient groups (P = .0013). Coronary aneurysms developed least frequently in patients treated with regimen 4 and less frequently with regimen 2 than with regimen 1 (P = .0730). Multiple regression analysis showed significant reductions of fever and coronary aneurysm incidence with prednisolone (P < .0001 and P = .0307, respectively). Conclusion: Our data suggest a possible role of corticosteroids in the treatment of the acute phase of KD. (J Pediatr 1999;135:465-9)