Because swallowing disorders are frequent in the elderly, we assessed the relationship between age and mylohyoideus muscle contraction, which is an important component of the initial step in swallowing. In a prospective study, 120 subjects without any personal history of diseases associated with swallowing disorders underwent electromyographic recording (EMG) of mylohyoideus muscle activity. Four groups of equal size (n = 30) were defined according to age (< or = 50, 51-70, 71-85, >85 years). The frequency and duration of mylohyoideus muscle asynchronisms were compared among the four groups. The comparison of mylohyoideus muscle EMG among groups did not show a significant difference in the mean number of asynchronisms, in duration per subject or in the frequency of long-lasting asynchronisms. Asynchronisms were a very frequent event, observed in 98% of subjects, and were mostly short, lasting less than 0.1 s in 90% of subjects. In healthy elderly patients, there was no linear relationship between the mean duration of asynchronisms and ageing. The occurrence of one or more long-lasting asynchronisms or of at least six asynchronisms during a sequence of 10 successive swallows should be considered to be abnormal.