Mycotoxins are microbial agents which cause food or feed-borne intoxications. Mycotoxins are undesireable compounds often found in cereal grains and forages. Production of mycotoxins is dependent on environmental conditions and agricultural practices. Moisture level ranges between 13% to 18% and temperatures between 20 C and 30 C can increase fungal growth rate during growing seasons as well as during transport and storage. Extensively, mycotoxins are aflatoxins (Afs), ochratoxin A (OTA), Fusraium and Patulin. Ochratoxin is naturally occurring mycotoxin produced by fungi Aspergillus and Penicillium. Family of ochratoxin consist of three member ochratoxin A, B and ochratoxin C. Ochratoxin A is most abundant and most toxic produced mainly by Aspergillus ochraceus, A. carbonarius and Penicillium verrucosum. Penicillium verrucosum mainly produced the ochratoxin A in cereals. A. ochraceus is responsible for ochratoxin A production in coffee, grapes and spices. Conclusively, findings of some researchers related to the mycotoxins, their production and concentration especially ochratoxin A in different cereal products and effect of processing on the ochratoxin A contents and its health implication on human health have been reviewed