A Gram negative, aerobic, non-motile and rod-shaped bacterial strain designated as Gr-2T was isolated from granules used in a wastewater treatment plant in Korea, and its taxonomic position was investigated using a polyphasic approach. Strain Gr-2T grew at 18–37°C (optimum temperature, 30°C) and a pH of 6.0–8.0 (optimum pH, 7.0) on R2A agar medium. Based on 16S rRNA gene phylogeny, the novel strain showed a new branch within the genus Pseudaminobacter of the family Phyllobacteriaceae, and formed clusters with Pseudaminobacter defluvii THI 051T (98.9%) and Pseudaminobacter salicylatoxidans BN12T (98.7%). The G+C content of the genomic DNA was 63.6%. The predominant respiratory quinone was ubiquinone-10 (Q-10) and the major fatty acids were cyclo-C19:0 ω8c, C18:1 ω7c, and iso-C17:0. The overall polar lipid patterns of Gr-2T were similar to those determined for the other Pseudaminobacter species. DNA-DNA relatedness values between strain Gr-2T and its closest phylogenetically neighbors were below 18%. Strain Gr-2T could be differentiated genotypically and phenotypically from the recognized species of the genus Pseudaminobacter. The isolate therefore represents a novel species, for which the name Pseudaminobacter granuli sp. nov. is proposed with the type strain Gr-2T (=KACC 18877T =LMG 29567T).