The authors present a review of their research work in an endeavor to interpret the behavior of zinc-rich paints (ZRP) using electrochemical impedance spectroscopy (EIS). This technique can provide much useful information about the protection mechanisms of ZRP. The tendency of some of these coatings to act like an electrode with a very large accessible internal area (that of the interconnected zinc particles) is examined. This situation favors the cathodic protection of the steel substrate by the zinc particles. The higher frequency arc chord in the Nyquist diagrams and the Warburg coefficient calculated from the low-frequency diffusion tail enables the extent and evolution of the coating barrier effect to be determined.