Attempts to find objective tests to assess nasal obstruction have a long history. The physiologic and pathologic fluctuations that occur within the nose over short periods of time have hampered these efforts, and all presently available techniques have significant drawbacks. The most commonly used is active rhinomanometry, and relatively recent standardization has led to the popularization of the anterior method. Posterior active and passive rhinomanometry are also available; other methods include plethysmography, peak expiratory flow rate, rhinohygrometry, thermography, oscillometry, echorhinometry, audiometric rhinomanometry, and rhinostereometry. A reliable technique would have many applications, particularly in pre- and post-therapeutic evaluation. At present, however, no method enjoys routine clinical usage, although there is considerable interest in future development.