Ochratoxin A (OTA) is the most toxic member of the ochratoxins group and one of the most important mycotoxins isolated and described to the present day. Teratogenic, embryotoxic, genotoxic, neurotoxic, immunosuppressive, carcinogenic (IARC group 2B), and nephrotoxic effects were also observed for OTA. OTA, mainly produced by Aspergillus ochraceus, Penicillium verrucosum, Aspergillus carbonarius, and, at lesser extent, by different species of black Aspergilli, occurs on several common commodities in human diets, including grapes, barley and green coffee beans. Moreover, it has been associated to Nephropathy Endemic of Balkans, and it is suspected to cause tumors of urinary system and interstizial chronic nephritis in Northern Africa. Regulation for OTA was established by the European Commission for several food commodities, among which raw cereal grains and cereal derived products.