Rationale: Cleaning tasks may imply exposure to chemical agents with potential harmful effects to the respiratory system, and increased risk of asthma and respiratory symptoms among professional cleaners and in persons cleaning at home has been reported. Long-term consequences of cleaning agents on respiratory health are, however, not well described. Objectives: This study aimed to investigate long-term effects of occupational cleaning and cleaning at home on lung function decline and airway obstruction. Methods: The European Community Respiratory Health Survey (ECRHS) investigated a multicenter population-based cohort at three time points over 20 years. A total of 6,235 participants with at least one lung function measurement from 22 study centers, who in ECRHS II responded to questionnaire modules concerning cleaning activities betweenECRHSI and ECRHSII, were included. The data were analyzed with mixed linear models adjusting for potential confounders. Measurements and Main Results: As compared with women not engaged in cleaning (Delta FEV1 = -18.5ml/yr), FEV1 declined morerapidly in women responsible for cleaning at home (-22.1; P = 0.01) and occupational cleaners (-22.4; P = 0.03). The samewas found for decline in FVC (Delta FVC = -8.8 ml/yr; -13.1, P = 0.02; and -15.9, P = 0.002; respectively). Both cleaning sprays and other cleaning agents were associated with accelerated FEV1 decline (-22.0, P = 0.04; and -22.9, P = 0.004; respectively). Cleaningwas not significantly associatedwith lung function decline in men or with FEV1/FVC decline or airway obstruction. Conclusions: Women cleaning at home or working as occupational cleaners had accelerated decline in lung function, suggesting that exposures related to cleaning activities may constitute a risk to long-term respiratory health.