Xanthoma disseminatum (XD) is a rare normolipemic mucocutaneous xanthomatosis due to the proliferation of non-x histiocytes. Occasional involvement of the upper respiratory system has been reported, but lower respiratory tract involvement is very rare. Here, we present a child with severe involvement of the upper and lower respiratory tract by XD and bronchiectasis in the lower lobes of both lungs. The patient was an 8-year-old boy who was admitted to our hospital because of red-brown papules which developed on the skin and progressive dyspnea. He was diagnosed as having XD by skin biopsy. Physical examination revealed disseminated, numerous yellow-reddish brown papularxanthomas on the forehead and eyelids, around the neck and axillary area, and in the oral cavity and pharynx. He had respiratory distress and clubbing of the fingers. Chest x-rays showed hyperaeration and segmental atelectasis. High-resolution CT of the thorax revealed diffuse thickening of the whole tracheal and bronchial wall, and bronchiectasis in the lower lobes. Flexible fiberoptic bronchoscopy revealed numerous xanthomatous lesions in the nasal cavity, nasopharynx, oropharynx, subglottic area, trachea, bifurcation, both main bronchi, and smaller bronchi. To the best of our knowledge, this is the first report of a child with typical lesions of XD with severe involvement of the lower respiratory tract and bronchiectasis. (C) 2004 Wiley-Liss, Inc.