The effect of cathodically active noble alloying elements, Ag, Pt and Au on the environmental behavior of hot pressed and sintered stainless steel in H2SO4 environment was investigated. It was found that Ag additions slightly improve the corrosion resistance and remain as inclusions in the sintered stainless steel. Pt additions of about 2 wt% were found to be sufficient to preserve the passive state. High Pt content results in high tendency for breakdown of the passive layer, due to very high cathodic activity. Au additions strongly affect pore morphology by decreasing the density of the open pores, most probably due to liquid phase sintering. The samples containing Au additions of various concentrations exhibit clear anodic active-passive transition with a wide range of passivation. Samples containing 5 wt% Au remain passive.