Background Few reports have documented the clinical characteristics and treatment outcomes of adult patients with Elizabethkingia meningoseptica infection. Methods Medical records of patients over 18 years of age and suspected of having an E. meningoseptica infection from March 1, 2006 to February 28, 2013 were reviewed retrospectively. Their clinical characteristics, antimicrobial susceptibility results, and treatment outcomes were analyzed. Results E. meningoseptica was isolated from 30 patients. Median age was 68.5 years, and infections were more frequent in males (17, 56.7%). The most common isolation source was sputum (23, 76.7%), and pneumonia was the most common condition (21, 70%) after excluding two cases of colonization. This bacterium was most susceptible to minocycline (27, 90%) and fluoroquinolones, including levofloxacin (20, 66.7%) and ciprofloxacin (18, 60%). The mortality rate due directly to E. meningoseptica infection was 20% (6/30), and uncontrolled pneumonia was the only cause of death. After isolating E. meningoseptica, the numbers of patients with pneumonia (9/9, 100% vs. 12/21, 57.1%), history of hemodialysis (5/9, 55.6% vs. 3/21, 14.3%), tracheostomy (8/9, 88.9 vs. 10/21, 47.6%), and median Charlson comorbidity index score (6 [range, 3–9] vs. 4 [range, 0–9]) were significantly higher in non-survivors than those in survivors (p < 0.05, for each). However, only 12 (40%) patients received appropriate antibiotics. Conclusions E. meningoseptica infection most commonly presented as pneumonia in adults with severe underlying diseases. Despite the high mortality rate, the rate of appropriate antibiotic use was notably low.