A novel strain, C-138(T), belonging to the genus Corynebacterium was isolated from a severe thigh liposarcoma infection and its differentiation from Corynebacterium xerosis and Corynebacterium freneyi is described. Analysis of 16S rRNA gene sequences, rpoB sequences and the PCR profile of the 16S-23S spacer regions was not conclusive enough to differentiate strain C-138(T) from C. xerosis and C. freneyi. However, according to DNA-DNA hybridization data, strain C-138(T) constitutes a member of a distinct novel species. It can be differentiated from strains of C. xerosis and C. freneyi by colony morphology, the absence of alpha-glucosidase and some biochemical characteristics such as glucose fermentation at 42 degrees C and carbon assimilation substrates. The name Corynebacterium hansenii sp. nov. is proposed for this novel species; the type strain is C-138(T) (=CIP 108444(T)=CCUG 53252(T)).