Three American infants with Kawasaki disease (KD) complicated by peripheral extremity gangrene are reported. Eight such patients (only 1 from Japan) have been reported previously. These 11 patients, infants less than 7 months old at onset of KD, are predominantly non-Asian. At least nine had associated giant coronary aneurysms, and eight had associated peripheral arterial aneurysms. In eight infants the diagnosis of KD was not established and therapy was not instituted until greater than or equal to 14 days after onset. Peripheral ischemia initially was noted 15-31 days after onset. Although the pathogenesis of this complication is not well understood, it likely includes some combination of local peripheral arteritis, arteriospasm, thrombosis peripherally and/or more proximally (e.g., in an axillary artery aneurysm), and cardiogenic shock. Treatment may include use of antiinflammatory agents such as salicylates and intravenous gamma globulin, vasodilative agents and/or methods, and thrombolytic and/or anticoagulant agents in an attempt to prevent the potentially devastating consequences of progressive gangrene.