Ergot alkaloids are mycotoxins produced by fungi of all species of the genus Claviceps, mainly by C. purpurea, which parasitize the seed heads of living plants during flowering. The group of ergot alkaloids are: ergotamine, ergometrine, ergocornine, ergosine, ergocryptine and ergocristine, and their isomers. The aim of this paper is to summarize the most relevant and timely information on ergot alkaloids. This also applies to information on their occurrence, toxicity, chemical properties, the statutory limits and their importance in animal feed.