Shewanella spp., which are known to carry chromosomally located bla _OXA genes, have mainly been isolated from marine environments; however, they can also cause infections in humans. In this study, we compared the molecular characteristics of clinical isolates of Shewanella spp. with those originating from environmental sources. All 10 clinical isolates were genetically identified as members of the Shewanella algae clade ( S. algae , S. chilikensis , and S. carassii ); however, all but one of the 13 environmental isolates were identified as Shewanella species members outside the S. algae clade.