The impact of respiratory infections on public health is increasing, and lower respiratory tract infections are a major cause of morbidity and mortality. Moreover, most antibiotic prescriptions are related to respiratory infections and this is probably one of the main determinants of the increasing rate of bacterial resistance in both community and hospital settings. This has been the catalyst for the development of new drugs, such as the new fluoroquinolones. The new fluoroquinolones have an excellent spectrum providing cover for the most important respiratory pathogens, including atypical and "typical" pathogens. The 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 post-antibiotic 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 LRTIs. This review discusses the most recent data on the bacteriological and clinical activity of the new fluoroquinolones and critically analyses the risks of a potential overuse of this valuable new class of drugs.