A 49-year-old-man was admitted to our hospital because of cough, wheezing, and dyspnea. Chest CT showed bilateral bronchocentric nodules and increased bronchial thickness. And he was given a diagnosis of bronchial asthma. However, another small airway disease, such as diffuse panbronchiolitis (DPB) was also suspected, and surgical lung biopsy was performed. The biopsy specimens showed a prominent peribronchial lymphoplasmacytic and eosinophilic infiltration with IgG4-positive plasma cells. IgG4-positive plasma cells may play a role in the pathogenesis of bronchiolar diseases associated with allergic airway inflammation.