The corrosion resistance of intermetallic NiAl, superalloy GH217 and an 18-8 stainless steel in molten carbonates at 923 K was determined by weight loss and electrochemical measurements. Morphology and structure of the corrosion products were characterized using a combination of electron probe and X-ray diffraction (XRD). The corrosion resistance of NiAl is the best among the materials investigated. NiAl produces more protective corrosion products and forms more complete oxide films on the surface than GH217 or 18-8 stainless steel.