A method of inhibiting corrosion of a metal surface in an aqueous system having a pH of at least 6, comprising maintaining in the aqueous system, in an amount effective to inhibit corrosion, a water-soluble, organic-rare earth metal chelate which is derived from a rare earth metal having an atomic number from 57 to 71 and an organic chelant. The organic chelant provides not only water solubility but surprisingly enhanced corrosion inhibiting activity. The water-soluble, organic-rare earth chelates may be advantageously combined with other corrosion inhibitors such as zinc chelates, organophosphonates, phosphates, chromates, molybdates, and the like.