Nitrogen (N) is often a yield-limiting nutrient in the production of maize. The identification of genes involved in nitrogen use efficiency (NUE) and the use of such genes to develop hybrids with greater NUE could have both economic and environmental benefits. The objective of this study was to identify QTL controlling NUE and its component traits. The mapping population used was a set of hybrids developed by crossing lines from the IBMRI population to the Illinois High Protein (IHP1) inbred. This population takes advantage of the high mapping resolution of the IBMRIs and the high N uptake phenotype of IHP1. A set of 243 hybrids was grown with and without supplemental N in an N-responsive environment. Measurements of plot yield, stover fresh weight, stover dry weight, stover N concentration, and grain protein, oil, and starch concentration were made and used to calculate NUE and its component traits. Results from the QTL analysis of these traits will be presented here