To determine differences in perception of nasal obstruction in Canadians and Japanese, we assessed subjective and objective nasal patency of 48 patients in Canada and 43 patients in Japan. Mean severity of the sensation of nasal obstruction in Canadian patients was significantly higher than in Japanese patients, while no significant differences in nasal resistances were found. Complaints of nasal obstruction in Canadian patients were directly concerned with nasal breathing, while Japanese patients complained of indirect matters, such as "unable to concentrate on job or study" or "nasal obstruction or nasal speech pointed out by other persons." The differences might be due to national characteristics.