Strain CC-SEYA-1T, a motile, Gram-negative, non-violet-pigmented bacterium, was isolated on nutrient agar from spring-water samples collected from Yang-Ming Mountain, Taipei County, Taiwan. 16S rRNA gene sequence studies showed that the strain clustered with Chromobacterium violaceum (96.8 % similarity) and Chromobacterium subtsugae (96.5 % similarity), followed by Aquitalea magnusonii (95.8 % similarity). The fatty acid profile was slightly different from those reported for C. violaceum, C. subtsugae and A. magnusonii. The results of DNA-DNA hybridization, and physiological and biochemical tests allowed both genotypic and phenotypic differentiation of the isolate from the described Chromobacterium species. It is evident from the data obtained that the strain should be classified as a novel species in the genus Chromobacterium. The name proposed for this taxon is Chromobacterium aquaticum sp. nov.; the type strain is CC-SEYA-1T (=CCUG 55175T=BCRC 17769T).