Abstract Because of their antimicrobial activity and pharmacologic properties, fluoroquinolones should be particularly suitable for the treatment of lower respiratory tract infections, although they might be less efficient in pneumococcal diseases. In fact, the overall clinical success rate of enoxacin, ofloxacin, pefloxacin, and ciprofloxacin is >85%, and their efficacy compares favorably with that of other antibiotics. For acute exacerbation of chronic bronchitis, however, β-lactam or macrolide agents probably remain a first choice unless sputum reveals gram-negative pathogens; in the same way, drugs other than quinolones seem better indicated in community-acquired pneumonia because of the prevalence of Streptococcus pneumoniae in these infections. In contrast, nosocomial pulmonary infections due to gram-negative pathogens should be excellent candidates for therapy with new quinolones. These drugs, used with or without erythromycin and rifampin, might be useful in the treatment of legionnaires' disease. This content is only available as a PDF. © 1989 by The University of Chicago