Corn-based food products obtained from commercial outlets in three different parts of the U.S., Maryland, Nebraska, and Arizona were analyzed for total fumonisins by a commercial competitive direct enzyme-linked immunosorbant assay (CD-ELISA) and for fumonisin B(1) (FB(1)) by high-performance liquid chromatography (HPLC). The highest fumonisin concentrations were found in samples collected in Maryland, where all 18 samples were found positive for fumonisins (200 to 7,450 ng/g of food) by CD-ELISA and 15 of the 18 samples (83%) were found positive for FB(1) (<75 to 5,916 ng/g) by HPLC, Fumonisins were also detected by CD-ELISA in 14 of 15 samples collected in Arizona, with concentrations ranging from 200 to 1,450 ng/g, but analyses by HPLC showed that only 8 of 15 samples (53%) were positive for FB(1)(<75 to 1,565 ng/g of food). Of the 23 samples collected in Nebraska, 20 (87%) were positive for fumonisins (200 to 2,500 ng/g) by CD-ELISA, but only 10 (44%) were positive for FB(1) (<75 to 927 ng/g) by HPLC. The highest fumonisin and FB(1) concentrations were found in cornmeal samples, ranging up to 7,450 ng/g of cornmeal by CD-ELISA and 5,916 ng/g by HPLC. These findings indicate that there may be a risk of human exposure to fumonisins through the consumption of some corn-based foods.