A novel Gram-negative, non-flagellated, non-gliding, rod-shaped bacterial strain, designated PB-M7(T), was isolated from the intestine of a sea cucumber collected from Pohang, South Korea. Growth was observed at 4-30 °C (optimum, 25 °C), pH 6.0-9.0 (optimum, pH 7.0-8.0), and with 2.0-6.0% (w/v) NaCl (optimum, 2.0%). In a phylogenetic analysis based on 16S rRNA gene sequences, strain PB-M7(T) was found to belong to the genus Bizionia and to be most closely related to Bizionia echini KMM 6177(T) (99.0% 16S rRNA gene sequence similarity), Bizionia hallyeonensis T-y7(T) (97.9%), Bizionia algoritergicola APA-1(T) (97.5%), Bizionia argentinensis JUB59(T) (97.5%) and Bizionia myxarmorum ADA-4(T) (97.1%). The predominant fatty acids of strain PB-M7(T) were identified as iso-C(15:0) (22.2%), iso-C(15:1) G (10.8%), iso-C(17:0) 3-OH (16.7%) and summed feature 3 (C(16:1) ω7c and/or C(16:1) ω6c; 11.2%). The major respiratory quinone was identified as menaquinone-6 (MK-6). The polar lipid profile of strain PB-M7(T) was found to contain phosphatidylethanolamine, an unidentified phospholipid, three unidentified aminolipids and three unidentified lipids. The DNA G + C content of strain PB-M7(T) was determined to be 33.4 mol% and the mean DNA-DNA relatedness values with the type strains of B. echini, B. hallyeonensis, B. algoritergicola, B. argentinensis, and B. myxarmorum were 52.9, 48.5, 46.5, 37.1 and 26.6%, respectively. Based on the data presented, strain PB-M7(T) represents a novel species of the genus Bizionia, for which the name Bizionia psychrotolerans sp. nov. is proposed. The type strain of B. psychrotolerans is PB-M7(T) (= KCCM 43042 (T) = JCM 19924 (T)).