Two novel exopolysaccharide-producing bacteria, strains S18K6(T) and S18K5, were isolated from Pacific Ocean sediment. The isolates were Gram-negative, motile, strictly aerobic chemoheterotrophic bacteria. The DNA G+C contents of strains S18K6(T) and S18K5 were 44.8 and 46.3 mol%, respectively. DNA-DNA relatedness between the two strains was 70 %. Major fatty acids were hexadecanoic acid (C(16 : 0)), hexadecenoic acid (C(16 : 1)omega7c) and octadecenoic acid (C(18 : 1)omega7c). 16S rRNA gene sequence, chemotaxonomic and morphological data indicated that these strains clearly belonged to the genus Glaciecola. Based on phenotypic properties and DNA-DNA hybridization data, strains S18K6(T) and S18K5 are considered to represent a novel species of the genus Glaciecola, for which the name Glaciecola chathamensis sp. nov. is proposed. The type strain is S18K6(T) (=JCM 13645(T)=NCIMB 14146(T)).