In nature, rare earths elements occur in multiple minerals. Today, they are used in medical technology, nuclear engineering, automobile industry, military devices and even in spacecraft. Furthermore, rare earth-containing drugs are used for the treatment of some health issues. In the future, among other uses, rare earths might be involved in cancer therapy, treatment and prevention of osteoporosis and atherosclerosis as well as organ transplantation. In China, rare earths have been successfully used at low concentrations as feed additives and fertilizers for decades. The results from studies from this country indicate that the use of rare earth elements improves liveweight gain and feed conversion in animals. The mechanism of action of these elements is not well understood but it is thought that they develop their activity in the digestive tract since very little is absorbed. Rare earth elements might be of interest in animal production as a new, safe and inexpensive alternative growth promoter. This review analysis the accessable literatre related to rare earth element usage in animal feed.