This paper attempts to estimate by means of a cross-sectional study in subjects aged 65 yrs and over the determinants of the prevalence of chronic bronchitis according to age, gender, smoking history, educational level, former occupation and associated morbidity. Data were examined from the third year of a cohort (Personnes àgêes QUID (PAQUID)) and concerned 2,406 subjects. Identification of chronic bronchitis was based on a direct question asking for the presence of phlegm on most days during at least 3 months per year for at least the two previous years. Of the sample, 13% reported chronic bronchitis (20% of males, and 8% of females). A multivariate analysis was performed and showed that chronic bronchitis was linked to sex, smoking history and professional category. Independent of these factors, asthma history and digitalic drug therapy were also closely associated to chronic bronchitis. These results underline the long-term effect of smoking and occupation on chronic bronchitis, and also illustrate the strong association with asthma and cardiac morbidity over 65 yrs of age.