Traditional clinical examination is frequently inadequate to evaluate children affected by chronic nasal obstruction: radiology may be of some use but it exposes children to radiation and gives only a limited lateral view of the nasopharynx. Therefore other means need to be tested for the anatomical and functional examination of the nasal and nasopharyngeal cavities. Adenoid hypertrophy and chronic nasal congestion are the most common causes of nasal respiratory impairment in children. The clinical expressions of adenoid enlargement are influenced by the osteo-cartilaginous nasal conformation and by functional alterations of nasal mucosa. Therefore a correct clinical examination is necessary to determine the indications for adenoidectomy so as to prevent unsatisfactory results. The aim of this study was to test the efficacy of rhinopharyngoscopy and rhinomanometry in the quantitative and qualitative evaluation of nasal and nasopharyngeal airways in 50 children (age-range 5-12 years) affected by nasal obstruction. Based on the rhinopharyngoscopic evaluation of adenoid volume, the children were divided into 3 groups affected by choanal obstruction defined as: severe (28 cases); partial (14 cases); minimal (8 cases). In these 3 groups anterior rhinomanometry, performed before and after administration of a nasal decongestant, allowed to evidence the role played by functional and organic factors in determining nasal stenosis. Abnormal values of total nasal resistance were found in 42 of the 50 children in the study. In 12 of these cases there was a marked decrease in nasal resistance following decongestion, evidencing the prevalence of functional factors in determining nasal obstruction and contra-indicating adenoidectomy. Rhinopharyngoscopy and rhinomanometry were well tolerated by all examined patients; the combined use of the two techniques allowed a more accurate diagnostic assessment of functional and anatomical causes of nasal obstruction in order to predict the benefits which can be obtained through adenoidectomy.