BACKGROUND: Recently, the number of elderly patients with bacteremia has been increasing in the emergency room. Klebsiella pneumoniae is the second common agent of all gram negative bacteremia. We designed this study in order to describe the clinical characteristics and outcomes of elderly patients with K. pneumoniae bacteremia in the emergency room. METHODS: We retrospectively reviewed medical records of 109 patients infected with K. pneumoniae, who visited an emergency room of a tertiary hospital from March 2006 to October 2010. All patients were divided into two groups (83 survivors versus 26 nonsurvivors). We compared the outcomes and the clinical characteristics between the two groups. RESULTS: A total of 26 patients (23.9%) died in this study. There were no significant differences in age, sex, previous medical and surgical history between survivor and nonsurvivor groups. In the univariate logistic regression analysis, the significant favorable factors for survival associated with K. pneumoniae bacteremia were malignancy (odds ratio [OR], 0.311; p=0.018), Charlson comorbidity index (OR, 0.787; p=0.010), intensive care unit admission (OR, 0.260; p=0.032), mean arterial pressure (OR, 1.053; p=0.001), body temperature (OR, 2.250; p=0.001), blood urea nitrogen (OR, 0.969; p=0.002), albumin (OR, 6.739; p<0.001) and lactate (OR, 0.876; p=0.046). In a multiple logistic regression, the significant risk factors for predicting mortality were low body temperature (OR, 1.036; p=0.044) and low serum albumin (OR, 5.636; p=0.002) at the time of admission. CONCLUSION: Initial albumin level and body temperature were significant risk factors of mortality in elderly patients in the emergency room infected by K. pneumoniae bacteremia. Elderly patients with K. pneumoniae bacteremia in the emergency room should be carefully observed due to the high mortality rate.