Breeding to improve soybean oil quality has intensified over the past decade. Stability of performance across environments is essential to consistent production of modified fatty acid levels. We conducted this study to determine fatty acid fluctuations across SD environments, hoping to verify that we can produce soybeans with modified fatty acid profiles in northern environments. We evaluated soybean lines with modified linolenic acid. Since certain fatty acids fluctuate with modification of others, we studied the fatty acids most likely to fluctuate with fluctuations in linolenic acid (oleic, linoleic, palmitic, and stearic). We tested 38 soybean lines in maturity groups 0, I and II derived from two crosses of high protein SD lines with two IA low linolenic parents. The low linolenic and high protein parents, along with three yield checks (group 0, I, and II) were included. All 45 lines were evaluated during 2004 growing season in three widely varied SD locations. Significant yield, protein, and oil variations were found among the 45 entries. There were significant environmental effects on yield, protein and oil. Genotype x environment interactions were not significant for yield. There were location, maturity group and genotype x location effects for palmitic, but not for stearic acid. There were significant variations among genotypes for both palmitic and stearic acid. There were significant location and maturity group effects for oleic, linoleic, and linolenic acid. Differences in linolenic acid among locations ranged from 0.4-0.9 percent. Significant variations among entries were found for all 3 fatty acids . Entry x location effects were significant for oleic and linoleic, but not for linolenic acid. Maturity group x location effects were significant only for oleic acid. These data indicated that fluctuation levels of linolenic acid may be acceptable, and each maturity group may have relatively wide adaptability across the region for this trait.