During the last 35 years, omega-3 polyunsaturated fatty acids have emerged as a topic of scientific scrutiny and public interest. In the 1970’s, epidemiological studies of Greenland Eskimos linked their diet, high in whale, seal, and fish rich in omega-3 polyunsaturated fatty acids, to a low incidence of cardiovascular mortality [1,2]. Further, research shows promising evidence indicating that moderate doses of omega-3 polyunsaturated fatty acids not only reduce the risk of cardiovascular disease, but decrease mortality due to myocardial reinfarction, sudden dearth, and overall mortality in patients with established coronary heart disease. While much research has been done to investigate omega-3 polyunsaturated fatty acids and the prevention of coronary heart disease few studies have focused on secondary prevention and myocardial reinfarction in populations with established coronary heart disease. Further, studies that investigate omega-3 polyunsaturated fatty acid therapy in patients with established coronary heart disease have shown an inconsistent association between n-3 polyunsaturated fatty acids intake and the risk of myocardial reinfarction. This study aims to investigate the protective properties of long chain omega-3 fatty acids, particularly DHA and EPA. This study will focus on both dietary and supplemental interventions in populations with established coronary heart disease and the prevalence of myocardial reinfarction, sudden dearth, and overall mortality.