OBJECTIVE: To review and discuss the effect of n-3 polyunsaturated fatty acids (PUFA) from fish in the prevention and, primarily, in the treatment of coronary artery disease (CAD). DESIGN: Overview of the literature. SETTING: Denmark. RESULTS: There is good evidence that fish consumption may reduce the risk of CAD. CONCLUSIONS: Fish can be recommended to reduce the risk of CAD both in healthy subjects and in patients with a high risk of CAD or with documented CAD. The use of fish oil concentrates can not be recommended in general, but may be considered in patients after a myocardial infarction or in patients with hypertriglyceridaemia. An increased intake of n-3 polyunsaturated fatty acids from fish may have substantial implications for public health and health economy by decreasing the risk of coronary events and sudden cardiac death.