Forty-six turkeys were inoculated intranasally with Bordetella avium at 3 days of age. Inoculated and non-inoculated turkeys (n = 72) were necropsied sequentially from post-exposure days (PED) 3 to 53. Tracheal lesions were studied histologically. Mild fibrinopurulent tracheitis, associated with bacterial colonization of ciliated epithelium, was seen at PED 7 to 10. At PED 14 and 21, there were numerous bacterial colonies, loss of ciliated cells, epithelial hyperplasia, depletion of mucus, and diffuse infiltration of lymphocytes and macrophages. At PED 28, the mucosa and tracheal rings were severely distorted. The mucosal epithelium, composed of immature epithelial cells and nononuclear leukocytes, had formed prominent longitudinal folds. Mucous glands were cystic and lined by low cuboidal epithelium. At PED 42 and 53, tracheas appeared normal, except for residual distortion of tracheal rings and shortened luminal epithelium.