A bacterial strain, designated CL-22T, was isolated from an encrusting pore coral, Montipora aequituberculata, collected off the coast of Southern Taiwan. Its taxonomic position was investigated using a polyphasic approach. Cells of strain CL-22T were Gram-stain-negative, aerobic, motile by means of a single polar flagellum, rod-shaped and formed yellow colonies. Optimal growth occurred at 30 °C, pH 6.5-7 and in 2 % (w/v) NaCl. A neighbour-joining phylogenetic tree, based on 16S rRNA gene sequences, showed that strain CL-22T fell into the clade comprising the type strains of species of the genus Thalassotalea. Strain CL-22T exhibited 16S rRNA gene sequence similarity values of 94.7-97.1 % to the type strains of species of the genus Thalassotalea. The major fatty acids (>10 %) of strain CL-22T were summed feature 3 (C16 : 1ω7c and/or C16 : 1ω6c) and C16 : 0. The predominant isoprenoid quinone was Q-8. The major polar lipids were phosphatidylethanolamine and phosphatidylglycerol. The genomic DNA G+C content of strain CL-22T was 41.2 mol%. The differential phenotypic properties, together with the phylogenetic inference, demonstrate that strain CL-22T should be classified as a novel species of the genus Thalassotalea; the name Thalassotalea montiporae sp. nov. is proposed. The type strain is CL-22T (=LMG 24827T=BCRC 17940T).