Fats in fish and marine animals are rich in highly unsaturated fatty acids (FA with 5 or more double bonds) of the Omega 3 series. These FA, present in aquatic animals as an adaptation to the environmental conditions, reached the human diet through the food chain, with a significant impact on nutrition, life style and cultural conditions. Studies in the 70's showed that high fish consumption is associated with better cardiovascular health and this observation was subsequently confirmed in many studies (epidemiological, cohort, case-control). The evidence is stronger for secondary prevention and when the intakes of fish or omega 3 FA are assessed, rather than just estimated. The major effects are reduction of cardiac, especially sudden, death. Underlying mechanisms concern the antiarrhythmic activities, reduction of thrombotic and inflammatory processes and of serum triacylglycerol levels. In conclusion consumption of fish and its components should be promoted on a global scale especially in the case of subjects with cardiovascular problems. Although still some issues need to be faced especially in large scale interventions (i.e. the assessment of the omega 3 fatty acid status, correlations between levels and cardiovascular indexes and bioavailability of different forms of administration), these recommendations are highly valuable.