Mycotoxins can cause toxicity when ingested by humans and animals. Although the rumen is supposed to be a barrier against mycotoxins, some studies demonstrate that carry-over of mycotoxins to milk is possible. Different studies have found mycotoxin levels in animal milk, mainly related to contaminated feed for ruminants. Aflatoxin M1 is the most studied mycotoxin in milk and levels exceeding the EU maximum level for this mycotoxin in this matrix (0.050 mu g/kg) have been found. Maximum levels in milk for other mycotoxins have not been established; however ochratoxin A, aflatoxins G1, G2, B1, B2 and M2, fumonisin B1, cyclopiazonic acid, zearalenone and its metabolites and deepoxy-deoxynivalenol have also been found in milk samples. Taking into account that multi-exposure to mycotoxins is the most likely scenario and co-occurrence of mycotoxins could affect their toxicological effects in humans and animals, there is a need to determine the co-occurrence of mycotoxins in milk.