A novel actinobacterial strain, designated SYSU K10001T, was isolated from a limestone sample collected from a karst cave in Xingyi county, Guizhou province, south-western China. The taxonomic position of the strain was investigated using a polyphasic approach. Cells of the strain were aerobic and Gram-stain-positive. On the basis of 16S rRNA gene sequence analysis, strain SYSU K10001T was most closely related to the type strains of the genus Lentzea, Lentzea albida NBRC 16102T (98.8 % similarity) and Lentzea waywayandensis NRRL B-16159T (98.6 %), and is therefore considered to represent a member of the genus Lentzea. DNA-DNA hybridization values between strain SYSU K10001T and related type strains of the genus Lentzea were less than 70 %. In addition, meso-diaminopimelic acid was the diagnostic diamino acid in the cell-wall peptidoglycan. The whole-cell sugars were arabinose, fructose, mannose and xylose. The major isoprenoid quinone was MK-9(H4), while the major fatty acids (>10 %) were iso-C16 : 0 and C14 : 0. The polar lipids were diphosphatidylglycerol, phosphatidylethanolamine, hydroxy-phosphatidylethanolamine, phosphatidylinositol, phosphatidylinositol mannoside, one unidentified phospholipid and one unidentified lipid. The genomic DNA G+C content of strain SYSU K10001T was 69.4 mol%. On the basis of phenotypic, genotypic and phylogenetic data, strain SYSU K10001T represents a novel species of the genus Lentzea, for which the name Lentzea cavernae sp. nov. is proposed. The type strain is SYSU K10001T (=KCTC 39804T=CGMCC 4.7367T=NBRC 112394T).