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Background: Bronchial hyperresponsiveness (BHR) is a common feature of asthma. However, BHR is also present in asymptomatic individuals and its clinical and prognostic significance is unclear. We hypothesised that BHR might play a role in the development of chronic obstructive pulmonary disease (COPD) as well as asthma. Methods: In 1991 respiratory symptoms and BHR to methacholine were evaluated in 7126 of the 9651 participants in the SAPALDIA cohort study. Eleven years later 5825 of these participants were re-evaluated, of whom 4852 performed spirometric tests. COPD was defined as an FEV1/FVC ratio of,0.70. Results: In 1991 17 % of participants had BHR, of whom 51 % were asymptomatic. Eleven years later the prevalence of asthma, wheeze, and shortness of breath in formerly asymptomatic subjects with or without BHR was, respectively, 5.7 % v 2.0%, 8.3 % v 3.4%, and 19.1 % v 11.9 % (all p,0.001). Similar differences were observed for chronic cough (5.9 % v 2.3%; p = 0.002) and COPD (37.9 % v 14.3%; p,0.001). BHR conferred an adjusted odds ratio (OR) of 2.9 (95 % CI 1.8 to 4.5) for wheezing at follow up among asymptomatic participants. The adjusted OR for COPD was 4.5 (95 % CI 3.3 to 6.0). Silent BHR was associated with a significantly accelerated decline in FEV1 by 12 (5–18), 11 (5–16), and 4 (2–8) ml/year in current smokers, former smokers and never smokers, respectively, at SAPALDIA 2