The electrochemical corrosion behavior of Fe(73.5-X)Cu1Nb3Si13.5B9CrX(0-5) FINEMET type alloys have been investigated in 0.5 N KOH solutions using potentiodynamic polarization and AC impedance spectroscopic techniques. Kinetic parameters were obtained after holding the samples at open-circuit potential for 20 min. The open-circuit potential of all specimens decreases with inmersion time, and a shift of stationary potential in the anodic direction was observed with the Cr addition. The present study attempts to correlate impedance data with polarization data and the results indicate that both values are comparable for passivated alloys. In the case of FINEMET type alloys, the addition of chromium results in the formation of a passive film which prevents the corrosion of the alloy and which can be represented by a single time constant equivalent circuit.