In order to assess a possible relationship between ageing and expiratory flow limitation (EFL), and the potential of the negative expiratory pressure technique (NEP) in the study of ageing, this technique was evaluated in 30 volunteers (10 young, 10 middle aged, 10 elderly) using a prototype of a NEP instrument developed in our laboratory.  Ageing caused a significant increase in EFL (ANOVA, p<0,02), that was ade-quately identified by NEP, whose parameters were closely associated with ageing (p<0,03). This data are consistent with previously published results and physiological fundamentals, confirming the high potential of NEP in the assessment of the modifications related to ageing.