Antibiotics help reduce the economic burden of 600,000 annual hospitalizations and added outpatient visits and days missed from work, school, and other activities due to community-acquired pneumonia (CAP). OBJECTIVES: To compare costs, outpatient visits, and 28-day outcomes with gatifloxacin versus ceftriaxone among adult patients with CAP. METHODS: Data were collected on health care resource use from 287 inpatients with CAP randomized to receive initial IV therapy with either gatifloxacin alone (GAT) or ceftriaxone +/- erythromycin (CEF). After at least two days of IV therapy, patients could be switched to oral therapy with GAT (GAT arm) or clarithromycin (CEF arm) at the treating physician s discretion. Total costs, which include medication, outpatient, and hospital costs, and the number of outpatient visits and days missed from work, school, and other activities were calculated. The analysis was limited to clinically evaluable patients. RESULTS: A total of 205 patients were clinically evaluable (99 GAT, 106 CEF). The mean total cost for the GAT arm was less than the CEF arm ($5,665 vs. $6,469; p=0.149). The mean total cost for patients admitted to the ICU was lower for patients.