In Kawasaki disease (KD), a systemic vasculitis of childhood, serum levels of proinflammatory cytokines such as tumour necrosis factor alpha (TNFalpha) are elevated during the acute phase of the disease. Although the majority of children recover completely from a single dose of intravenous immunoglobulin (IVIG), the treatment is not always effective. In refractory cases of KD there are no documented treatment guidelines. A future role of biological agents directed against proinflammatory cytokines has recently been suggested by the American Heart Association (AHA). We describe two infants with severe KD, complicated by coronary as well as extracoronary aneurysms, who responded neither to repeated treatment with IVIG plus aspirin nor to corticosteroids. The children were subsequently treated with infliximab. In both cases, the effect was prompt and long-lasting. Clinical improvement was seen within a few days after the first dose, and regression of the aneurysms occurred within weeks.