Purpose: Chronic rhinosinusitis (CRS) is related to asthma and chronic obstructive pulmonary disease (COPD). However, combined data on CRS, pulmonary function, lower airway symptoms, and cigarette smoking from the general population are lacking. The current study investigates the relationships between CRS and chronic airflow limitation (CAL), lower airway symptoms and COPD in a middle-aged population of ever-smokers and never-smokers. Patients and Methods: All subjects from the Swedish CArdioPulmonary bioImage Study (SCAPIS) were included. Subjects underwent spirometry after bronchodilation. Chronic airflow limitation was defined as FEV1/FVC ratio <0.7. Computed tomography imaging of the thorax was performed to detect the presence of emphysema, and the subjects answered a comprehensive questionnaire on CRS, lower airway symptoms, asthma, chronic bronchitis, and cigarette smoking habits. Results: In total, 30,154 adult subjects in the age range of 50-64 years were included. The prevalence of CRS was 5.6%. CRS was more-prevalent among subjects in the following categories: CAL (7.6%), lower airway symptoms (15.7%), current smokers (8.2%), asthma (13.6%), never-smokers and ever-smokers with COPD (17.6% and 15.3%, respectively), emphysema (6.7%), and chronic bronchitis (24.5%). In the adjusted regression model, CRS was significantly associated with CAL (OR 1.40), lower airway symptoms (OR 4.59), chronic bronchitis (OR 6.48), asthma (OR 3.08), and COPD (OR 3.10). Conclusion: In this national, randomly chosen population sample of more than 30,000 middle-aged men and women, CRS is associated with CAL, lower airway symptoms, chronic bronchitis, asthma, and COPD. In patients with CRS and in patients with lower airway inflammation, it is important to consider the inflammatory status of the entire airway system.