Soybean [Glycine mar (L.) Merr.] seeds contain high levels of protein and oil useful for human consumption. Increasing emphasis in breeding programs to produce soybeans with specific protein or oil content for specialty markets demands that more efficient manipulation of these traits be achieved. The objective of this study was to evaluate eight different soybean populations from the midwestern USA for genetic markers linked to seed protein and oil content. The populations were derived from the breeding programs at the Univ. of Minnesota, the Univ. of Nebraska, and Purdue Univ.-USDA-ARS. Each population consisted of between 69 and 100 individuals and was mapped with 21 to 85 restriction fragment length pollymorphism markers. The [F.sub.2]derived populations were grown in field tests in 1992, 1993, and 1994 in the state in which they originated. Single factor analysis of variance was used to detect significant associations between markers and traits. Environmentally stable and environmentally sensitive quantitative trait loci (QTL) were identified for both protein and oil contents in all eight populations. The identified QTL were sensitive to both environment and genetic background although some common QTL were identified in multiple populations across several years. The results show that a number of QTL affect these traits and that markers could potentially be used in breeding programs designed to alter the seed protein and oil content.