The frequencies of nasal and bronchial ciliated cell beats were compared in 10 adult subjects (mean age 56 years) with E.N.T. tumoral pathology but no recent respiratory disease. Ciliated cells were collected by simultaneous nasal curettage and bronchial brushing carried out under general anaesthesia during endoscopic evaluation of the tumors. The frequency of beats was measured by the stroboscopic method at room temperature (18 degrees-25 degrees C) at least 3 hours after cell collection. A significant (p less than 0.05) difference was found between nasal (8.89 +/- 0.84 Hz) and bronchial (9.6 +/- 1.03 Hz) beats. A study of nasal ciliated cell beats therefore provides a first assessment of ciliary function which is of interest in patients with recurrent respiratory diseases. It is a simple procedure that can easily be performed prior to more complex investigations, such as study of the bronchial ciliated cell beats or ultrastructural study of the cilia.