The casein phosphopeptides (CPP) are derived from the milk protein casein by tryptic digestion. The CPP, containing the sequence -Pse-Pse-Pse-Glu-Glu- where Pse is a phosphoseryl residue, stabilize calcium and phosphate ions in aqueous solution and make these essential nutrients bioavailable. Under alkaline conditions the calcium phosphate is present as an alkaline amorphous phase complexed by the CPP, referred to as casein phosphopeptide-amorphous calcium phosphate (CPP-ACP). The CPP-ACP complexes readily incorporate fluoride ions forming casein phosphopeptide-amorphous calcium fluoride phosphate (CPP-ACFP). A mechanism is discussed which provides a rationale for the ability of the CPP-ACP to remineralize carious lesions in dental enamel. Clinical applications of the CPP-ACP as agents in the treatment of dental caries and other hypomineralized conditions are reviewed. It is concluded that the CPP are a safe and novel carrier for calcium, phosphate and hydroxide (fluoride) ions to promote enamel remineralization with application in oral care products, dental professional products and foodstuffs.