Background: Methicillin-resistant Staphylococcus aureus (MRSA) has been recognized as an important cause of not only hos-pital acquired pneumonia but also community acquired or healthcare associated pneumonia (HCAP). The objectives of this study was to identify factors associated with MRSA. Methods: We retrospectively evaluated patients hospitalized to Severance Hospital with culture positive pneumonia developed outside of the hospital from January 2009 to December 2010. Results: Of 451 patients, MRSA was identified in 37 (8.2%) patients. The mean age was higher in MRSA than non-MRSA groups (72.8 years old vs 66.7 years old; P＜0.001). Male was more dominant in both groups (75.7.% in MRSA vs 65.2% in non-MRSA; P=0.198). Comparing the treatments and outcomes, the frequency of initial treatment with glycopeptide antibiotic was similar between the groups (16.2% in MRSA vs 13.5% in non-MRSA, P=0.649). However, 14 (37.8%) patients in MRSA and 86 (20.8%) in non-MRSA died (P=0.017). In a logistic regression, previous history of MRSA infection (OR=5.87, P＜0.001), prior hospitalization within 90 days (OR=3.92, P=0.003), Multiple infiltrates on chest radiograph (OR=2.29, P=0.046), and age (OR=1.05, P=0.021) were independently associated with MRSA pneumonia. Conclusions: Empiric therapy with coverage for MRSA should be considered in patients with non hospital-acquired pneumonia having risk factors such as previous history of MRSA infection, prior hospitalization within 90 days of pneumonia, multiple infiltrates on chest radiography and old age.