An aerobic, Gram-stain-negative, rod-shaped and polar-flagellated bacterium, designated strain CC-MHH0089 T , was isolated from a soil sample taken on Matsu Island (Taiwan). Strain CC-MHH0089 T grew at 15-30 6C and pH 5.0-10.0 and tolerated ¡8 % (w/v) NaCl. 16S rRNA gene sequence analysis showed high pairwise sequence similarity to Pseudomonas azotifigens 6H33b T (97.3 %) and Pseudomonas balearica SP1402 T (96.7 %) and lower sequence similarity to other strains (,96.0 %). In DNA-DNA reassociation experiments, the relatedness of strain CC-MHH0089 T to P. azotifigens JCM 12708 T was 38.3 % (reciprocal value 19.5 %). Evolutionary trees reconstructed on the basis of 16S rRNA, gyrB and rpoB gene sequences revealed a varying phylogenetic neighbourhood of strain CC-MHH0089 T with regard to the most closely related type strains. The predominant quinone system was ubiquinone 9 (Q-9) and the DNA G+C content was 63.6 mol%. The major fatty acids were C 12 : 0 , C 16 : 0 , C 17 : 0 , C 19 : 0 cyclo v8c and summed features 2 (C 14 : 0 3-OH/iso-C 16 : 1 I), 3 (C 16 : 1 v7c/C 16 : 1 v6c) and 8 (C 18 : 1 v7c/C 18 : 1 v6c). The major polar lipids were phosphatidylcholine, phosphatidylglycerol, phosphatidylethanolamine and diphosphatidylglycerol. According to its distinct phylogenetic, phenotypic and chemotaxonomic features, strain CC-MHH0089 T is proposed to represent a novel species within the genus Pseudomonas, for which the name Pseudomonas matsuisoli sp. nov. is proposed. The type strain is CC-MHH0089 T (5BCRC 80771 T 5JCM 30078 T ).