A marine bacterial strain, designated FR1311T, was isolated from a sea-water sample from Ganghwa Island, South Korea. Cells were Gram-negative, facultatively anaerobic, catalase- and oxidase-positive, motile, oval or rod-shaped and halophilic (optimum sea-salt concentration for growth of 5-6 %). Phylogenetic analysis of its 16S rRNA gene sequence revealed that it represented a distinct line of descent within the genus Photobacterium. The major fatty acids were straight-chain saturated (C(16 : 0)) and monounsaturated fatty acids (C(16 : 1)omega7c and C(18 : 1)omega7c). The predominant respiratory lipoquinone was Q-8. The DNA G+C content was 44 mol%. The phenotypic features of strain FR1199T were similar to those of Photobacterium damselae subsp. damselae and Photobacterium damselae subsp. piscicida, but several physiological and chemotaxonomic properties readily distinguish the new isolate from them. On the basis of the polyphasic results revealed in this study, FR1311T is considered to be the type strain of a novel species, for which the name Photobacterium ganghwense sp. nov. is proposed. The type strain is FR1311T (=IMSNU 60287T = KCTC 12328T = JCM 12487T).