There is a lack of evidence about whether menopausal status influences the effect of smoking on lung function. This study examined the association between smoking and menopausal status and lung function independent of each other. Data were from a cohort of women attending the 21-year follow-up of the Mater University of Queensland Study of Pregnancy. The study was based on 2020 women who provided data on respiratory function, smoking, and menopausal status. A Spirobank G spirometer system was used to measure forced vital capacity (FVC), forced expiratory volume in first second (FEV(1)), and forced expiratory flow between 25 and 75% of forced vital capacity (FEF(25-75)). Smoking and menopausal status were assessed by self-report. Respiratory function was associated with cigarette smoking, menopausal status, and hormone replacement therapy. Regardless of smoking status, postmenopausal women had poorer lung function when compared with premenopausal women. In multivariate analysis, cigarette smoking was associated with lower FVC, FEV(1), and FEF(25-75), with the magnitude of effect being stronger for women who were postmenopausal. The data suggest that the impact of smoking intensifies after menopause. It seems plausible that effective quit-smoking programs, particularly after menopause, may lead to better lung function and reduced morbidity and mortality in women.