Elizabethkingia meningoseptica (Chryseobacterium meningoseptica) is a ubiquitous Gram-negative bacillus in the natural and hospital environments. This microorganism causes neonatal meningitis but rarely causes infections in adults, with most adult cases occurring in severely immunocompromised patients. Since E. meningoseptica is inherently resistant to the usual empiric therapy aimed at Gram-negative bacilli and MIC breakpoints for resistance and susceptibility of E. meningoseptica have not been established by the Clinical and Laboratory Standards Institute, it is very difficult to select effective antibiotics for the treatment of E. meningoseptica infection. We report here three cases of E. meningoseptica isolates (two from blood and one from CSF) from adult patients admitted to Seoul St. Mary’s hospital over a 3-year period. To the best of our knowledge, this is the first report of adult meningitis due to E. meningoseptica in Korea. (Korean J Clin Microbiol 2011;14:153-157)