Three isolates obtained from grass samples were investigated by means of a polyphasic taxonomic study and were shown to represent a novel species within the genus Chryseobacterium. Comparison of 16S rRNA gene sequences and phenotypic features indicated that the three isolates belonged to a single species. On the basis of 16S rRNA gene sequence analysis, the closest phylogenetic neighbours were Chryseobacterium shigense and Chryseobacterium vrystaatense, which formed a stable cluster with the isolates; this phylogeny was supported by a high bootstrap value and was obtained using different treeing methods. A DNA-DNA hybridization study with the closest neighbour, C. shigense DSM 17126(T) (98.3 % 16S rRNA gene sequence similarity), clearly demonstrated a separate species status for the grass isolate strain P 456/04(T). Comparisons involving physiological properties and whole-cell fatty acid profiles confirmed this result at the phenotypic level. On the basis of these results, strain P 456/04(T) represents a novel species of the genus Chryseobacterium, for which the name Chryseobacterium luteum sp. nov. is proposed. The type strain is P 456/04(T) (=DSM 18605(T) =LMG 23785(T)).