OBJECTIVE: We assessed associations between physical activity and lung function, and its decline, in the prospective population-based European Community Respiratory Health Survey cohort. METHODS: FEV1 and FVC were measured in 3912 participants at 27-57 years and 39-67 years (mean time between examinations=11.1 years). Physical activity frequency and duration were assessed using questionnaires and used to identify active individuals (physical activity >/=2 times and >/=1 hour per week) at each examination. Adjusted mixed linear regression models assessed associations of regular physical activity with FEV1 and FVC. RESULTS: Physical activity frequency and duration increased over the study period. In adjusted models, active individuals at the first examination had higher FEV1 (43.6 mL (95% CI 12.0 to 75.1)) and FVC (53.9 mL (95% CI 17.8 to 89.9)) at both examinations than their non-active counterparts. These associations appeared restricted to current smokers. In the whole population, FEV1 and FVC were higher among those who changed from inactive to active during the follow-up (38.0 mL (95% CI 15.8 to 60.3) and 54.2 mL (95% CI 25.1 to 83.3), respectively) and who were consistently active, compared with those consistently non-active. No associations were found for lung function decline. CONCLUSION: Leisure-time vigorous physical activity was associated with higher FEV1 and FVC over a 10-year period among current smokers, but not with FEV1 and FVC decline.