(1) The risk-benefit ratio of antibiotic therapy in exacerbations of chronic bronchitis is uncertain. If an antibiotic is considered, fluoroquinolones are at best second-line options, after betalactam agents such as amoxicillin, and macrolides. (2) For community-acquired pneumonia the first-line antibiotics are betalactam agents such as amoxicillin, and macrolides. Patients with severe disease should receive combination therapy with a betalactam and a macrolide or a fluoroquinolone. (3) Acute sinusitis generally resolves spontaneously. If an antibiotic is prescribed, fluoroquinolones are at best second-line options, after betalactam agents such as amoxicillin, and macrolides. The value of systemic antibiotic therapy is also controversial in chronic sinusitis and chronic otitis media; once again, fluoroquinolones are not agents of first choice. (4) Fluoroquinolones share many adverse effects, especially neuropsychiatric, cutaneous, tendon, and cardiac involvement. They can also damage cartilage in children. They are contraindicated in pregnant women. They potentiate oral anticoagulants.