An actinomycete strain, designated YU1183-22(T), was isolated from a compost sample collected in Nikko, Japan. The isolate formed white aerial mycelium with relatively long aerial hyphae showing chains of arthrospores. Strain YU1183-22(T) grew with 0-10 % (w/v) NaCl, at pH 6-11 and at 10-37 °C (optimum 30 °C). Strain YU1183-22(T) contained meso-diaminopimelic acid and no diagnostic sugars. The predominant menaquinones were MK-10(H(10)) and MK-10(H(8)). The polar lipids were phosphatidylcholine and phosphatidylglycerol. The major cellular fatty acids were iso-C(16 : 0), anteiso-C(17 : 0) and tuberculostearic acid. The G+C content of the DNA was 72.3 mol%. Chemotaxonomic and morphological characterization clearly demonstrated that strain YU1183-22(T) belonged to the genus Nocardiopsis. Phylogenetic analysis using 16S rRNA gene sequences showed that the isolate was closely related to Nocardiopsis salina YIM 90010(T) (98.0 % 16S rRNA gene sequence similarity), Nocardiopsis xinjiangensis YIM 90004(T) (97.9 %) and Nocardiopsis kunsanensis HA-9(T) (97.3 %). However, DNA-DNA relatedness as well as physiological and biochemical analyses showed that strain YU1183-22(T) could be differentiated from its closest phylogenetic relatives. It is proposed that this strain be classified as a representative of a novel species of the genus Nocardiopsis, with the name Nocardiopsis nikkonensis sp. nov. The type strain is YU1183-22(T) (=NBRC 102170(T) =KCTC 19666(T)).