To evaluate the nasal mucosal changes in rhinitis medicamentosa (RM), especially those related to goblet cells and subepithelial glands, we studied specimens of the inferior turbinate mucosa from 8 patients with RM, 8 patients with chronic hypertrophic rhinitis (CHR), and 5 patients with normal nasal mucosa. All specimens were assessed by electron microscopy and immunohistochemical study. Under a scanning electron microscope, hyperplasia of goblet cells was most prominent in the RM group, and an increased number of gland openings was evident in the RM and CHR groups. In addition, the immunoreactivity of epidermal growth factor receptor staining was strongest in the hyperplastic epithelium of the RM group. According to our results, it is feasible that the mucosa of patients with RM is in a chronic inflammatory, hypersecretory state. Degenerative changes in the secretory elements may cause impairment of mucociliary transport and may be responsible for the nasal obstruction and posterior nasal drip in RM.