A yellow-pigmented, Gram-staining-negative, aerobic, non-motile, moderately thermophilic, rod-shaped bacterium, CC-MHSW-2T, was isolated from a coastal hot spring of Green Island (Lutao), located off Taituang, Taiwan. The 16S rRNA gene sequence analysis demonstrated that it shared <93.2% sequence similarity with Aquimarina species. The organism was unable to produce acid from carbohydrates, but it could utilize a number of organic acids and amino acids. Menaquinone 6 (MK-6) was the major respiratory quinone and iso-C15:0, iso-C17:0 3-OH and summed feature 3 (comprising C16:1omega7c and/or C16:1omega6c) were the predominant fatty acids. This fatty acid profile distinguished the isolate from members of the genera Aquimarina, Tamlana, Zhouia, Leeuwenhoekiella and Cellulophaga. The DNA G+C content of strain CC-MHSW-2T was 39.7+/-1 mol%. On the basis of the 16S rRNA gene sequence analysis and the chemotaxonomic and physiological data, strain CC-MHSW-2T represents a novel genus and species in the family Flavobacteriaceae, for which the name Lutaonella thermophila gen. nov., sp. nov. is proposed. The type strain is CC-MHSW-2T (=KCTC 22538T=JCM 15069T).