A primary focus for soybean breeders in recent years has been development of sound agronomic cultivars with improved oil qualities such as reduced palmitic acid (16:0) and linolenic acid (18:3). A backcross program utilizing improved germplasm lines with low 16:0 (<4%) and low 18:3 (<4%) as donor parents and MG VII (Hagood) and MG VIII (Maxcy) cultivars as recurrent parents was used to develop modified fatty acid breeding lines. Objectives were: (1) to determine the effect of location on South Carolina (SC) experimental lines (BC1 and BC2) exhibiting reduced levels of 16:0 and/or 18:3 and (2) to evaluate progress in combining acceptable seed yield and agronomic traits with reduced fatty acid levels. Eight experimental lines and the cultivars Soyola, Dillon, Maxcy, and Hagood were planted at three locations in SC from 2001 to 2004. Agronomic performance was measured and seed were analyzed for protein, oil, and fatty acid levels. Results indicate significant differences between locations and genotypes for protein, oil, and fatty acid levels. There were significant genotype x location interactions for protein, oil, and fatty acid levels. Differences between locations and genotypes were also observed for seed yield and agronomic traits. Some experimental lines compared favorably with check cultivars for agronomic performance at some locations but overall mean seed yields of experimental lines were lower.