We tested the feasibility of using fungal metabolites produced by Trichoderma spp. to inhibit aflatoxin production by Aspergillus parasiticus. Using a cellophane-based method, seven biocontrol-related Trichoderma strains tested for their ability to secrete metabolites that block the synthesis of aflatoxin, known liver and lung carcinogen in A. parasiticus. Results demonstrate that water-soluble metabolites secreted by candidate strains,Trichoderma viride and T. harzianum have the ability to target aflatoxin production with minimal effect on A. parasiticus growth.