Increased concentrations of neutrophils and alveolar macrophages are recovered in the bronchoalveolar lavage (BAL) of smokers compared with non-smokers. We designed a study to determine the relationship between neutrophils and alveolar macrophages recovered by BAL and the degree of air-flow obstruction, measured by spirometry (chronic air-flow obstruction was defined as: FEV1 < 80% of predicted and FEV1/FVC ratio < 70% of predicted) in healthy smokers. We found a significant correlation between spirometric values and the number of neutrophils and alveolar macrophages in BAL fluid obtained from healthy smokers. Our findings suggest that counts of 13-15x1000 neutrophils/ml and/or 430-450x1000 alveolar macrophages/ml in BAL fluid could be used as markers of air-flow obstruction in smokers.