Acute exacerbations occur frequently in patients with chronic bronchitis and the majority of these patients benefit from antimicrobial therapy. The ideal antimicrobial agent for the management of acute exacerbations of chronic bronchitis (AECB) should have good activity against the common bacterial pathogens associated with these exacerbations (non-typable Haemophilus influenzae, Moraxella catarrhalis and pneumococci); it should be resistant to bacterial betalactamases; penetrate well into pulmonary tissues and secretions; kill bacteria without inducing excessive airway inflammation; be easy to take (given once or twice a day) in order to ensure high patient compliance, and be cost-effective. Fluoroquinolone antibiotics have demonstrated efficacy in the treatment of AECB, but because of the limited activity of certain older agents in this class when administered in standard doses against Streptococcus pneumoniae, they have not be extensively used for this indication. Newer agents including levofloxacin, grepafloxacin, sparfloxacin and trovafloxacin have excellent activity against both Gram positive and Gram negative pathogens likely to be involved in AECB. These agents can be administered once daily, making patient compliance and a successful therapeutic outcome more likely. The new quinolones offer promising alternatives for antimicrobial therapy in outpatients with AECB, particularly those with underlying co-morbidity and severe obstruction.