Soybean oil quality is determined by the relative composition of monounsaturated and polyunsaturated fatty acids in seed triacylglycerols. Elevated levels of oleic and reduced levels of linolenic acid confer oil stability, and, therefore, eliminate the need for hydrogenation, that leads to undesirable trans fatty acids. Thus, breeding efforts are focused on the incorporation of the high oleate trait into soybean germplasm. However, the quantitative inheritance of oleate trait and the lack of stability of some oleate phenotypes across environments, mainly due to temperature effects during oil deposition, render breeding for high oleic acid content cumbersome. The main objective of this study was the estimation of the genetic variances and heritabilities of soybean quality and agronomic traits, placing emphasis on oleate and linolenate traits. Moreover, the genotypic and phenotypic correlations between oleic and linolenic acid content with other fatty acid and agronomic traits, such as yield, height, flowering and maturity, were estimated. The study included three populations of 721 F5- , 118 F5- and 231 F3-derived lines from the crosses of N98-4445A x N97-3525, N97-3363-3 x PI423893 and N98-4445A x PI423893, respectively. The three populations, segregating for genes affecting oleate and linolenate traits, were grown in replicated trials in six, five and one environments, respectively, in NC during the growing seasons of 2005 and 2006. The results of this study will determine whether phenotypic selection for oleate and linolenate traits is effective when practiced on a plot or on an entry basis at different generations. Furthermore, the genetic correlations will provide insights into favorable, as well as unfavorable, responses to selection.