Mycotoxins are toxic molecules produced by multiple fungal species, including Aspergillus and Fusarium. Fungal infection of crops can result in mycotoxins entering the animal and human food supply. Enzyme-linked immunosorbent assays and other immunological assays have been developed to detect mycotoxins in foods. To calibrate the response of those methods, reference materials with known amounts of homogeneously dispersed mycotoxins are often utilized, where the mycotoxin concentrations have been determined using high-performance liquid chromatography coupled with absorbance or fluorescence detection methods, or high-performance liquid chromatography coupled with mass spectrometry detection methods. Therefore, it is important that the analytical methods provide accurate and precise quantitation of mycotoxins. The reference materials must also contain homogeneously dispersed known quantities of mycotoxin. To evaluate the accuracy and precision of mycotoxin reference materials and the analytical methods, quantitative results from multiple laboratories were completed each year for several years on ground corn check samples containing known levels of mycotoxins. Results for the quantitation of aflatoxin-containing corn reference samples are presented in this article. Keywords: mycotoxins; analysis; contaminated food utilization; interlaboratory study