In community-acquired pneumonia (CAP), a relapse of pulmonary infections after effective treatment with antibiotics is one of the clinical concerns; however, few studies are available to predict a relapse of respiratory infections. We therefore investigated whether inflammatory markers are useful to predict a relapse of respiratory infections in outpatients with CAP. Sixty-six outpatients with CAP were enrolled in this study. They received moxifloxacin (MFLX) at 400 mg once per day and were evaluated for clinical efficacy and cure rate. The levels of WBC, CRP, SAA, and PCT were measured on day 1, days 3-4, and day 7 from the start of MFLX treatment. In the 66 patients, 63 (95.5%) were clinically improved by a 7-day MFLX therapy. Among them, 58 (87.9%) had no need for retreatment after 28 days (referred to as curative cases), but 5 patients (7.6%) were treated with antibiotics that were different from what they had first been treated with; they had all experienced a relapse of pulmonary infection within 28 days (referred to as noncurative cases). The mean levels of WBC, CRP, SAA, and PCT on day 1, days 3-4, and day 7 after the MFLX treatment were almost equivalent in curative and noncurative cases; however, the change rates of CRP and SAA during the 7 days were significantly different between the 2 groups. Our findings suggest that these CRP and SAA rates are useful as predictors of the relapse of respiratory infection in outpatients with CAP.