The availability of a new generation of quinolones expands the choices of antimicrobials for therapy of acute exacerbations of chronic bronchitis. These agents have broad antimicrobial activity, including good in vitro activity against respiratory pathogens, and advantageous pharmacokinetic characteristics, including bronchial tissue penetration. Ciprofloxacin, enoxacin, ofloxacin, and temafloxacin have been evaluated in a number of clinical trials, compared to the reference agents ampicillin, amoxicillin (with and without clavulanate), cefaclor, doxycycline, and erythromycin. Ciprofloxacin, ofloxacin, and temafloxacin have generally demonstrated greater clinical success than enoxacin. While these agents are effective against many respiratory pathogens, Streptococcus pneumoniae and Pseudomonas aeruginosa infections appear to pose problems. Temafloxacin and ciprofloxacin have been compared; temafloxacin eradicated S. pneumoniae more efficiently and did not interact with theophylline. Fluoroquinolones are an important addition to the agents useful for bacterial exacerbations of chronic bronchitis.