A 3-year-old boy developed acute pulmonary edema following 6 months of recurrent fevers and thrombocytosis. Echocardiography demonstrated moderate-to-severe insufficiency of both mitral and aortic valves. Angiography and intravascular ultrasound were used to diagnose this unusual presentation of Takayasu's arteritis. To the best of our knowledge, this is the first histological demonstration of acute and chronic inflammatory changes in the mitral valve in these circumstances.