Dissolution of stainless steel type 304 in artificial saliva was studied by electrochemical methods, electron spectroscopy for chemical analysis, and atom absorption spectroscopy. The samples were polarized in the -400 mV (saturated calomel electrode) to -50 mV (saturated calomel electrode) range. The total thickness of the passive film was found to be 25 ± 3 A, independent of the potential. The passive film consists of a duplex structure: an inner laye r of (Cr0.5Fe0.5)xO3 and an outer layer of a mixture of Cr(OH)3 and (CrxFey)PO4.2H2O. The analysis indicated that 1 1 ug/cm2 of the alloying elements were disollved during exposure for 1 year.