Background: Correlation between upper and lower airway always been an interesting topic in thepast decades, showed by the emerging of “one airway one disease” concept. Nasal polyposis is a chronicinflammatory disease of the upper respiratory tract mucosa. How nasal polyposis affects or relates to thelower respiratory tract is still debatable. Purpose: to evaluate the impact of nasal polyposis on the lowerrespiratory function.Methods: This study was done in the ENT Department and Pulmonology - InternalMedicine Department Cipto Mangunkusumo Hospital from March to December 2003. It was a comparativecross-sectional study between polyposis group and non-polyposis group, with 29 subjects each. Subjectsunderwent skin prick test and spirometry examinations. Vital capacity (VC), forced expiratory volumeat the first one second (FEV1) and FEV1Dampak poliposis hidung terhadap fungsi ventilasi paru1/VC ratio values were gathered. Statistic calculations performed using independents t-test and Pearson chi-square.Results: Spirometry datas showed VC %prediction andFEV%prediction values in nasal polyposis group were lower than in non-polyposis group (68.33% and62.36% vs 78.66% and 70.65%, p < 0.05), but not significant for FEV1061 /VC ratio score (83.88 vs 83.18,p > 0.05). Patterns of lung ventilatory function, the percentage of lung ventilatory function disorderbetween the polyposis group and the control group is significantly different (58.7% vs 31%, p< 0.05).Using 2x2 table calculation, prevalence ratio was 1.9 (CI 95% 0.002-0.498).Conclusion: Polyposisgroup showed significant lower values of VC % prediction and FEV1 1% prediction. Percentage of lungventilatory function disorder in polyposis group is significantly higher than control.