Controlled microbial catabolism of sterols can meet biotechnological applications. Three soil-screened strains: Rhodococcus sp. CIP 105335 (strain GK1), strain GK3 and strain GK12 were found to possess a high capability for sterol degradation. These were identified according to their morphology, morphogenetic cycle, physiology and cell wall chemo type to belong to the genus Rhodococcus. Besides, cholesterol oxidase of rhodococci is either released free and/or linked into the cell surface layer. This typical location was determined for the three strains and confirmed their appurtenance to the specified genus. The nucleotide sequence of the 16S rRNA gene, determined for GK1 and GK12, showed that the strain GK1 might be a R equi or a closely related species, and the isolate GK12 is a strain of Rhodococcus erythropolis.