Several studies have shown that high intake of trans fat is associated with increased risk of chronic diseases especially cardiovascular disease. The levels of trans fat in the American diet is of concern. Structured lipid is a lipid that has been modified from its native form either by biocatalysts or chemical catalysts. These modifications result in change in the triacylglycerol molecular species which further alters the physicochemical properties such as melting properties, solid fat content, and oxidative stability of lipids. The process allows the production of a wide range of functional and nutritional lipids that may meet consumer needs. Enzymatically synthesized structured lipids can be used as a substitute for conventional lipids in trans-free margarine formulations. This article gives an overview of trans fatty acids and enzymatic modification of lipids for producing trans-free margarine.