Mycotoxins are substances produced by fungi that are poisonous to humans and other animals. Important mycotoxic fungi are either parasites or saprophytes of cereal and pulse crops and include species of Claviceps, Aspergillus, Penicillium, and Fusarium. Mycotoxins produced (notably ergot alkaloids, trichothecenes, and aflatoxins) have caused many epidemics in the human populations of various countries throughout the history and in the current age. They can severely impact on our food and livestock production and must be managed through programs of active surveillance and management.