Concerns over the trans fatty acid content of foods and the effects of cold temperature on biodiesel have sharply increased awareness and interest about the fatty acid composition of soybean oil. Soybean oil typically contains lower than desirable mono-unsaturated and higher than desirable poly-unsaturated fatty acid concentration. Breeding and variety selection have been proposed as the most effective way to improve soybean fatty acid ratios. This study had the objective to determine the fatty acid composition of soybean varieties entered in the 2004 Wisconsin Soybean Variety Test program. The ratio between mono- and poly-unsaturated fatty acids varied widely (1.7 to 3.9) among varieties across the thirteen sites tested. Also, there was no correlation between fatty acid ratios and the grain yield of soybean varieties. The results suggest that Wisconsin soybean growers could select soybean varieties that would have significantly lower mono- to poly-unsaturated fatty acid ratio and provide better oil for the food and fuel industry without compromising yield potential.