A Gram-positive, aerobic, non-motile, short rod, designated SMC46(T), was isolated from a spent mushroom compost sample collected in the Suwon region, South Korea. 16S rRNA gene sequence analysis revealed that strain SMC46(T) was a member of the family Microbacteriaceae; however, the isolate formed a branch separate from other genera within the family. Sequence similarity between strain SMC46(T) and other members of the family Microbacteriaceae was ≤97 %, the highest sequence similarity being with Frigoribacterium faeni 801(T) and Frondihabitans australicus E1HC-02(T) (both 97.0 %). Some chemotaxonomic properties of strain SMC46(T) were consistent with those of the family Microbacteriaceae: MK-11 and MK-12 as the predominant menaquinones, anteiso-C(15 : 0), iso-C(16 : 0) and anteiso-C(17 : 0) as the major cellular fatty acids and diphosphatidylglycerol, phosphatidylglycerol and an unidentified glycolipid as the polar lipids. However, strain SMC46(T) contained a B-type peptidoglycan not previously found in the family Microbacteriaceae. The DNA G+C content was 68 mol%. On the basis of phenotypic, chemotaxonomic and phylogenetic distinctiveness, strain SMC46(T) was considered to represent a novel genus and species in the family Microbacteriaceae, for which the name Compostimonas suwonensis gen. nov., sp. nov. is proposed. The type strain of the type species is SMC46(T) ( = KACC 13354(T) = NBRC 106304(T)).