Abstract: An analytical method for the simultaneous determination of cortisone acetate,prednisone,hydroprednisone,triamcinolone,dexamethasone and dexamethasone acetate in cosmetics using LC-MS/MS was developed. Cosmetic samples were extracted by acidified methanol and analyzed by LC-MS/MS using an electrospray source. The separation was carried out on a Shimadzu Shim-pack VP-ODS C₁₈ (150 mm×2.0 mm,5 μm) and the mobile phase consisted of methanol-0.1% formic acid solution (60∶40). The established method is suitable for routine monitoring and determination of glucocorticoids added in cosmetics illegally.