The elderly are at increased risk for respiratory tract infections. To evaluate the safety and efficacy of gatifloxacin in adults of any age with community-acquired respiratory tract infections, this open-label, multicenter, noncomparative study in community-based practices enrolled male and female outpatients at least 18 years old with a clinical diagnosis of community-acquired pneumonia (CAP), acute-bacterial exacerbation of chronic bronchitis (AECB), or acute uncomplicated maxillary sinusitis. Gatifloxacin 400 mg was administered once daily for seven to 14 days. Of 14781 clinically evaluable patients, 2505 were at least 65 years old, 499, at lest 80. Cure rates for CAP, AECB, and sinusitis ranged from 91.6% to 95.5% for patients less than 65 years old, 91.1% to 96.2% for those 65 to 79 years of age, and 89.5% to 94.8% for those at least 80 years old. Each age group, including patients with concomitant cardiovascular or diabetic conditions, tolerated treatment well. Gatifloxacin is efficacious and well tolerated in adult outpatients of any age with respiratory tract infections and is an important therapeutic option, particularly in communities with a high prevalence of resistant pathogens.