The impact of respiratory infections on public health is increasing and lower respiratory tract infections are a major cause of morbidity and mortality. We are also facing a worldwide burst of antibiotic bacterial resistance. The new fluoroquinolones have an excellent spectrum covering the most important respiratory pathogens, including atypical and 'typical' pathogens. Pharmacokinetic and dynamic properties of the new fluoroquinolones have a significant impact on their clinical and bacteriological efficacy. They cause a concentration-dependent killing with a sustained postantibiotic effect. Fluoroquinolones combine exceptional efficacy with cost-effectiveness. Not surprisingly, different guidelines have inserted these agents among the drugs of choice in the empirical therapy of community-acquired pneumonia. This review discusses the more recent data on bacteriological and clinical activity and critically analyses the risks of a potential overuse of this valuable new class of drugs.