Metallic glass wires were tested using potentiodynamic anodic polarization to determine the effect of crystallinity, alloy additions, and metalloid (silicon and boron) concentrations on the corrosion behaviour of FeSiB glassy alloys in 0.1 NH 2SO 4 at 303 K. Crystallization anneals resulted in a decrease in the corrosion resistance of Fe 67Cr 8Si 10B 15 metallic glass. The addition of as little as 3.75 at.% Cr can passivate Fe 75Si 10B 15 metallic glass while the additions of 3.75 at.% Ta or Nb did not result in passivation. It was found that increasing the chromium level to about 7 at.% improved the stability of the passive films of Fe 77.5−xCr xSi 7.5B 15 and Fe 75−xCr xSi 10B 15. The Fe 75−xCr xSi 15B 10 alloy showed the highest passive film stability, independent of chromium content from 5 to 7 at.%. Increasing the silicon-to-boron ratio from 0.4 to 1.5 also increased the corrosion resistance of FeCrSiB glass wire, especially at the lower chromium concentrations.