Technical Abstract: The amount and composition of crop residues added to soil in agricultural systems can influence decomposition processes and soil organic matter levels. This study aimed to evaluate residues (quantity and quality) of different corn cultivars commonly used in Brazilian cropping systems. The experiment was conducted for two seasons (2005/06 and 2006/07) on a Rhodic Ferralsol Eutric soil at the Monsanto Company Experimental Station, Rolândia County, Paraná State, Brazil. Ten corn cultivars that represent five degrees of breeding development (i.e., landrace, commercial variety, double cross, triple cross, and single cross hybrids) were evaluated. At final harvest, carbon (C) and nitrogen (N) of non-yield residue and grain were determined. Except for grain C, other measures (grain N concentration, residue C and N concentration, and C:N ratio) varied among cultivars. In general, the hybrids (particularly single cross hybrids) had higher residue C, and lower residue N concentrations than the landraces and commercial varieties. Findings suggest that breeding selection may have altered residue production and composition which may influence soil C dynamics.