Obstructive lung disease (OLD) is a risk factor for postoperative pulmonary complications (PPC) and is incidentally discovered during preoperative evaluation. The key treatments for OLD are inhaled long-acting bronchodilators (LAB). However, the advantage of preoperative bronchodilator treatment for patients with OLD remains unclear. The aim of this study is to elucidate the effect of preoperative LAB treatment in patients with untreated OLD on postoperative outcomes. In this propensity-matched cohort study, we included patients who were referred to the pulmonologists for untreated OLD. The patients were either treated with LAB or left untreated. The primary outcome was the incidence of prolonged oxygen therapy (>3days) in the postoperative period. We evaluated patients' characteristics with and without the use of LAB using propensity score (PS) matching weight. Subsequently, the outcomes in the two groups were compared. We analysed 614 patients; 132 patients were part of the LAB group and 482 were included in the control group. In the crude analysis, the incidence of prolonged oxygen therapy was higher in the LAB group than in the control group (odds ratio [OR]=1.35; P=0.04). However, after PS matching weight, no statistically significant differences in prolonged oxygen therapy (OR=1.15), incidence of prolonged intensive care unit stay, endotracheal re-intubation postoperatively and in-hospital death between the groups were identified. There is a limited benefit of preoperative treatment with inhaled LAB for the reduction of PPC in patients with untreated OLD.