A novel Gram-positive, anaerobic, and coccus-shaped bacterium, designated as strain ChDC B134(T), was isolated from a human postoperative infectious lesion in the right maxilla between the lateral incisor and canine and was characterized by polyphasic taxonomic analysis. 16S rRNA gene sequence analysis revealed that the strain ChDC B134(T) belonged to the genus Peptoniphilus, as it showed sequence similarities to Peptoniphilus indolicus KCTC 15023(T) (94.0 %) and Peptoniphilus asaccharolyticus KCTC 3321(T) (93.8 %). The prevalent fatty acids of of strain ChDC B134(T) were C16:0 (20.3 %), C18:1 cis 9 (34.3 %), and C18:0 (13.2 %). The DNA G+C content was 30.9 mol%. The cell wall diamino acid was d-ornithine, which is a property shared by other reference type strains of the genus Peptoniphilus. Based on the results of phenotypic, chemotaxonomic, and phylogenetic analysis, strain ChDC B134(T) (=KCOM 1628(T) = KCTC 15227(T) = JCM 30223(T)) should be classified as the type strain of a novel species of genus Peptoniphilus, for which the name Peptoniphilus mikwangii sp. nov. is proposed.