The anodic oxidation of bismuth metal in aqueous tartaric acid solutions is studied using electrochemical and photoelectrochemical techniques. The oxidation process comprises four stages : active anodic dissolution, primary passivation by a semiconductor oxide layer formation, secondary passivation due to salt layer formation at the oxide film/electrolyte interface and further growth of the oxide sublayer by a high-held transport mechanism. The chemical nature of the salt film was determined by ex-situ X-ray diffraction to be very close to normal bismuth tartrate Bi-2(C4H4O6)(3).6H(2)O. Electrophysical characteristics of the oxide sublayer point to its identification with Bi2O3.