A novel bacterium was isolated from a traditional fermented food, kimchi. The morphology, physiology, biochemical properties and 16S rRNA gene sequence of strain L133(T) were studied. Strain L133(T) was Gram-reaction-positive, catalase-negative and homofermentative, with rod-shaped cells that formed cream colonies. Cells grew in the presence of 0-5 % (w/v) NaCl (optimum, 1-2 %), at pH 5.0-9.0 (optimum, pH 7.0-8.0) and at 15-37 °C (optimum, 25 °C). Comparative 16S rRNA gene and pheS sequence analysis of strain L133(T) indicated that the strain belonged to the genus Lactobacillus. The major fatty acids were identified as C18 : 1ω9c, C16 : 0 and C18 : 0, and the cell wall contained peptidoglycan of the L-Lys-D-Asp type. DNA-DNA relatedness values between strain L133(T) and related species were below 11±0.4 %. The DNA G+C content of strain L133(T) was 35.7 mol%. Analysis of 16S rRNA gene sequences, as well as physiological and biochemical tests, identified genotypic and phenotypic differences between strain L133(T) and other species of the genus Lactobacillus. Based on these analyses, strain L133(T) is proposed to be a novel species of the genus Lactobacillus, named Lactobacillus kimchiensis. The type strain is L133(T) ( = KACC 15533(T) = JCM 17702(T) = DSM 24716(T)).