I do not think that it is controversial, if it is used appropriately. The controversy lies in using ineffective antimicrobials, which may prolong morbidity and increase hospitalization for pneumonia or respiratory failure. Early generation cephalosporins, for example, are no longer effective against β-lactamase producing Haemophilus influenzae (13). Therefore, alternatives are needed to reduce morbidity and mortality, and I think that many studies in the last 10 years have nicely defined which patients will benefit from antimicrobial treatment. Data from the Stockley group (8,14) in Birmingham as well as publications in London have convincingly demonstrated that a purulent exacerbation in COPD patients is strongly connected with high bacterial load and significant inflammation, and that antimicrobial treatment would shorten the period of recovery. The negative influence of purulent exacerbation on the natural course of the disease was also demonstrated (15).