In this paper, a statistical overview of the simultaneous presence of 14 mycotoxins in Spanish barley is presented. The co-occurrence of more than two mycotoxins has been observed in 95% of the samples. From a descriptive standpoint, the results show that the most common combinations were AFB1, OTA and DON (29%), and AFB1, OTA, DON and ZEA (26%), although other combinations could also occur. However, the statistical study determined that other associations had a higher impact or importance. Four factors or combinations of variables could explain the 63% of variability found for the samples. These factors were the associations of: type-B trichothecenes and DAS; type-A trichothecenes and NIV; AFB1, AFG1 and ZEA; and AFB2 and AFG2. The toxin-producing fungi and environmental conditions have been essential in explaining the associations between the toxins. (C) 2012 Elsevier Ltd. All rights reserved.