Abstract: The ability of two Aspergillus flavus Link isolates (CT3 and K49) to reduce aflatoxin contamination of corn was assessed in a four-year field study (2001 to 2004). Soil was treated with six wheat inoculant treatments: toxigenic isolate F3W4; the non-toxigenic isolate K49; the non-aflatoxigenic isolate CT3, two mixtures of CT3 or K49 with F3W4; and an autoclaved wheat control, applied at 20 kg/ha. In 2001, inoculation with the toxigenic isolate increased corn grain aflatoxin levels by 167% compared to the non-inoculated control, while CT3 and K49 inoculation reduced aflatoxin levels in corn grain by 86% & 60%, respectively. In 2002, inoculation of CT3 and K49 reduced aflatoxin levels by 61% and 76% compared to non-inoculated controls, respectively. In 2001 mixtures of toxigenic and non-toxigenic isolates had little effect on aflatoxin levels, but in 2002 inoculation with mixtures of K49 and CT3 reduced aflatoxin levels 68 and 37% compared to non-inoculated controls, respectively.