The damages of nasal epithelium could be one of the important causes of nasal mucosal hypersensitivity. In our previous study, the relationship between the status of nasal epithelium and histamine sensitivity were studied in patients with perennial allergic rhinitis and in normal subjects. We found that most of the histamine-reactive group showed desquamation of epithelial cells or increase goblet cells and most of the histamine non-reactive group showed squamous metaplasia in nasal epithelium. From above results, we are sure that there is a damage of nasal epithelium in patients with allergic rhinitis. However, we could not exclude the possibility of iatrogenic trauma during the biopsy procedure in interpreting the damage of nasal epithelium. The aim of this study is to evaluate the clinical usefulness of PAP stain in patients with allergic rhinitis. First, we investigated the degree of degeneration of epithelial cells and squamous metaplasia in patients with allergic rhinitis according to histamine sensitivity and we compared these results with those of normal subjects. Next, we investigated whether goblet cells in nasal mucosa of allergic rhinitis increase or not. The results were as follows : Squamous metaplasia in the histamine non-reactive group was greater when compared to the histamine reactive group in both perennial allergic rhinitis and normal subjects. The ratio of goblet cells to columnar cells was not increased in patients with allergic rhinitis. Degenerated columnar cells were discovered significantly less in the allergic rhinitis group when compared to normal subjects. However we could find no grading difference between the histamine-reactive and non-reactive group of allergic rhinitis. These results suggest that the use of Papanicolaou stain in nasal smears is a useful tool to evaluate the status of nasal epithelium.