A tendency for a decreased incidence of chronic sinusitis, milder pathology and increased nasal allergy have recently been reported. In this regard, the author conducted cytodiagnosis of nasal secretion and questionnaire survey for 3 years from 1985 to 1987 in the northern region of Izu peninsula in Shizuoka prefecture where no otolaryngolgy specialist was residing and no otolaryngological examination was conducted. The present study discusses the results of cytodiagnosis and the questionnaire survey. As compared to the urban area, the ratio of sinusitis patients was higher in the region (agricultural, forestry and fishing region) with no otolaryngology specialist. Though there was some difference depending on the residential area, the incidence was high in younger pupils and tended to go down in older pupils. The ratio of thosewith nasal allergy was the highest in the suburb and factory area, followed by urban area. It was the lowest in the agricultural, forestry and fishing region where no examination was conducted in the past. Compared with sinusitis, the fluctuation of incidence between school age in the same school was less despite a great difference by residential area. The ratio of correspondence of the questionnaire reply with the cytodiagnosis was significantly higher in nasal allergy cases than sinusitis cases. It is therefore advisable to bear in mind of about 30% confidence limit when extracting the two major nasal diseases of sinusitis and nasal allergy from the questionnaire survey results only. The present study did not prove a relation between the living environment and the nasal allergy incidence.