While corn, Zea mays L., is known to be a host for the root-knot nematode (RKN), Meloidogyne incognita, no information is available on the effects of root feeding on the plant. Interest in the relationship between RKN and corn has primarily focused on corn as a rotation crop with cotton and the use of hybrids that would help control nematode populations. The purpose of this research was to determine whether there is a relationship between root feeding by RKN, grain yield and contamination of grain with aflatoxin. Three southern-adapted commercial hybrids were each grown in three years (2005, 2006 and 2007) 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 populations to compare to non-fumigated plots with high nematode populations. Early (pre-plant), mid, and late (at harvest) season nematode population levels were estimated based on soil samples. Fumigated plots had significantly higher yields than the non-fumigated plots, but aflatoxin contamination levels did not differ between the two treatments.