Community acquired pneumonia (CAP) remains a prevalent and potentially life threatening illness. American Thoracic Society and Infectious Disease Society America recommend combination therapies with ${eta}-lactam$ plus a macrolide or a fluoroquinolone monotherapy for the empirical treatment of CAP. The aim of this study was to compare moxifloxacin monotherapy with cephalosporin plus azithromycin combination therapies. From January 2004 to March 2005, 18 patients in the moxifloxacin group(MG) and 21 patients in the cefuroxime or ceftriaxone plus azithromycin group(CAG) with CAP were retrospectively reviewed with regard to clinical, laboratory and microbiological data. Each patient was stratified into mild (risk class I-II), moderate (risk class III) and severe (risk class VI, V) group according to and PSI (Pneumonia Severity Index) score. Each group was compared for microbiological eradication, clinical assessment, the length of hospital stay. As results, Total 39 patients with CAP were reviewed. The appropriateness of admission was 83.3% in MC vs. 76.2% in CAC. The mean length of the hospital day was for 8.31 days vs. 7.39 days, days switching parenteral to oral antibiotics in 5.19 days vs. 5.28 days, clinical improvement in 2.43 days vs. 2.61 days in MG vs. CAC. Radiological improvement required 3.75 days vs 3.63 days in MG vs. CAG and bacteriological eradication rate at discharge was the same in the both groups. Mortality rate was 11.1% (2 of 18) vs 14.3% (3 of 21) in MG vs. CAG (p=0.77). Drug cost of the mean 5 hospital days requiring parenteral antibiotics was the most inexpensive in moxifloxacin group for the 147,045 won, and ceftriaxone 1g-azithromycin group for the 170,285 won, cefuroxime bid-azithromycin group for the 207,800 won, ceftriaxone 2g-azithromycin group far the 220,570 won, cefuroxime tid-azithromycin group for the 251,700 won. There was no significant statistical difference in clinical, bacterial, radiological cure and hospital days, and switch to oral days. In conclusion, that i.v. moxifloxacin monotherapy was as effective as azithromycin plus cefuroxime or ceftriaxone combination therapies fur the treatment of CAP. In drug cost analysis, moxifloxacin is less expensive than CAG.