Aromatic organosulfur compound, thianthrene (TA), was degraded by dibenzothiophene (DBT) desulfurizing strains Gordonia sp. TM414, and Rhodococcus erythropolis KA2-5-1, but not by benzothiophene (BT) desulfurizing strain R. jostii T09. Analysis of the acidic ethyl acetate extract of the culture broth revealed that TA-sulfoxide, TA-sulfone, and 2-phenylsulfanylphenol were formed, suggesting that the degradation pathway was similar to the 4S pathway with DBT. Thianthrene desulfurization is possible using Rhodococcus sp., which is a closely related taxa with Gordonia spp.