Five years after a cross-sectional survey concerning the small airways disease within a working population aged 18 to 66 years, the authors carried on a new study within the same sample of population (272 subjects) using the same methodology of research : standard questionnaire and spirometry (VC, FEV1, FEV1/VC, MEF 25-75/VC). The goal of this study was to assess the functional outlook of the individuals depending on the functional status recorded in the frame of the first study, i.e. normal ventilatory status, small airways disease, advanced bronchial obstruction. The results showed that after five years there is a worsening of the ventilatory status, mostly in men and in aged persons at start. This worsening arises from the movement from one category to another towards the advanced bronchial obstruction. This movement was reversible from small airways disease to normal status. Conversely, the movement from small airways disease to advanced bronchial obstruction was irreversible. This study shows that small airways disease is an intermediate condition between normal status and advanced bronchial obstruction. Three risk factors were put in evidence both for small airways disease and for movement towards advanced bronchial obstruction : male sex, aging and tobacco smoking.