We report a case of a 75-year-old man having unusual manifestation of thymic carcinoma associated with endobronchial metastases. To our knowledge, endobronchial metastases secondary to thymic carcinoma has not been reported in the literature. On high-resolution computed tomograms, the tree-in-bud centrilobular opacities caused by metastatic cells accumulating within the small bronchioles is indistinguishable from that caused by inflammatory process. Thus, in patients with thymic carcinoma and persistent tree-in-bud centrilobular opacities, endobronchial metastatic disease should be considered.