We describe seven cases of invasive fibrous tumors of the trachea and major bronchi with distinctive histologies and patterns of growth. The tumors are composed of proliferating fibroblasts and have moderate nuclear pleomorphism and low mitotic activity. The tumors bear some resemblance to inflammatory pseudotumor of the lung, fibrous histiocytoma, and fibromatosis, but differ from each of these entities. The tumors are neoplastic and invade down to or between plates of cartilage. Because of their proximal location, these tumors are usually amenable to sleeve resection. Recurrence is possible. Metastasis has not occurred. Distinction from more malignant mesenchymal tumors of the trachea and bronchus will prevent unnecessarily radical surgery.