Both Omega-6 and Omega-3 fatty acids are essential nutrients important for cellular structure and function but cannot be synthesized by the human body and must be obtained from food. These two classes of fatty acids are metabolically and functionally different and antagonistically regulate many physiological and pathological processes. Thus, the relative balance between Omega-6 and Omega-3 fatty acids are critical for good health. However, today’s diet contains too much Omega-6 but too little Omega-3, leading to a severe imbalance with a very high Omega-6/Omega-3 ratio (>10) in most people. Many lines of evidence suggest that this imbalance is a key factor contributing to the development of modern chronic diseases. A growing number of studies ranging from laboratory research to clinical trials have shown that balancing the tissue ratio of Omega-6/Omega-3 fatty acids by increasing tissue levels of Omega-3 fatty acids and/or decreasing the content of Omega-6 fatty acids are very beneficial for the prevention and treatment of many life-threating chronic diseases as well as for health promotion of the general public. Therefore, development and production of foods rich in Omega-3-fatty acids should be considered as a key health program to balance essential fat intake and thereby improve the nutritional and health status of all people.