The physical evaluation of the nasal cavity and paranasal sinuses has been improved by recent advances in diagnostic endoscopic systems and computerized tomography. Today, nasal endoscopy is considered to be the only comprehensive diagnostic rhinoscopic examination and computerized tomography has replaced the standard plain film roentgenograms in the initial evaluation of the paranasal sinuses. Advances have also been made in the evaluation of nasal functions, particularly in the assessment of obstruction. Rhinomanometry is the only method of objective assessment of the patency of the nasal cavities and makes it possible to perform nasal provocation tests. Today, this method of exploration should not be overlooked. Secretory function may be assessed by various methods: nasal cytology, quantification of inflammatory mediators in nasal cavity washing, and biochemical analysis of nasal secretions (albumin/protein ratio). Mucociliary function can be evaluated by measuring the nasal mucociliary clearance, by determining the frequency of cilia strokes (after brushing of the nasal mucosa and microscopic examination under stroboscopic light) and by election microscopic ultra-structure studies. Other methods of exploration which do not yet have a practical application are currently being investigated: rheologic studies of the mucus, immunologic evaluation of nasal secretions and acoustic rhinometry.