Aflatoxin, a toxin produced by the fungus Aspergillus flavus, is the most potent carcinogen found in nature. Aflatoxin contamination of maize is a chronic problem in the southern US, where high temperatures, water stress, and insect damage produce conditions conducive to infection of maize by A. flavus. The purpose of this research was to determine the relationship between two biotic stresses, leaf feeding by the fall armyworm (FAW), Spodoptera frugiperda, and root feeding by the root-knot nematode (RKN), Meloidogyne incognita, and contamination of grain with aflatoxin. In the first experiment, five hybrids (four commercial and one aflatoxin resistant) were grown in a split-plot design with whole plots representing FAW artifically infested or non-infested conditions and split-plots representing a hybrid. FAW damage was evaluated at seven and fourteen days after infestation. In the second experiment, three commercial hybrids were grown in a randomized complete-block design in a field with high population densities of RKN. A fumigant nematicide was used to create plots with minimal nematode damage to compare to non-fumigated plots with a high level of nematode damage. Early (pre-plant), mid, and late (at harvest) season nematode population levels were estimated based on soil samples. In both experiments plots were randomly assigned for evaluation for yield, aflatoxin contamination under natural conditions, or aflatoxin contamination under artifical infestation. Aerial digital imaging (FAW experiment only) and meausres of photosynthesis were used to evaluate plant stress during the course of the growing season. Correlations between plant damage, plant stress, and yield and aflatoxin contamination can be used to evaluate the significance of particular biotic stresses on aflatoxin contmaintion of maize and determine the focus of genetic improvement and crop management programs.