To investigate whether the airway inflammatory process is different in patients with chronic bronchitis with airflow limitation and those with chronic bronchitis without airflow limitation, we obtained bronchial biopsies from 14 subjects with chronic sputum production and fixed airway obstruction, and from 10 subjects with chronic sputum production and normal FEV1, all with a history of cigarette smoking. Paraffin-embedded and frozen bronchial biopsies were examined by immunohistochemistry to identify the number of neutrophils (neutrophil-elastase), eosinophils (antieosinophil cationic protein [EG-2]), mast cells (tryptase), T-lymphocytes (CD3), T-lymphocyte subpopulations (CD4 and CD8), B-lymphocytes, and macrophages (CD68) in the submucosa. Subjects with chronic bronchitis with airflow limitation had a greater number of T-lymphocytes (p < 0.01) and macrophages (p < 0.05) than subjects with chronic bronchitis without airflow limitation, whereas the T-lymphocyte subpopulations and the numbers of B-lymphocytes, neutrophils, eosinophils, and mast cells were similar in the two groups. When all the subjects were considered together, the number of T-lymphocytes correlated inversely with the values of FEV1 (r = 0.46, p < 0.02). In conclusion, airflow limitation in subjects with chronic bronchitis is associated with an increased number of T-lymphocytes and macrophages in the bronchial mucosa.