Abstract.In animal models of arterial thrombosis, fish‐oil‐enriched diets have been shown to have an antithrombotic effect. There is strong evidence, however, that this only holds if the fish‐oil consumption is associated with a reduction of the saturated fat intake. In animal models of atherosclerosis the effect of a marine diet is not consistent. Although in some studies with cod‐liver oil (which is relatively low in saturated fatty acids) a beneficial effect is observed, studies with other, more saturated fish oils do not confirm this. The influence of fish‐oil consumption on some thrombotic complications of human atherosclerosis is not well documented. So far, the few results reported are not very promising, but it should remembered that this mainly concerns short‐term studies. Studies with respect to human fibrinolysis are equivocal. Evidence has been obtained that fish consumption may even have an adverse effect on certain aspects of the fibrinolytic process. The studies performed so far do not provide conclusive evidence as to the importance of fish‐ and fish‐oil‐enriched food for prevention and therapy of ischaemic cardiovascular disease. Further research is needed, especially with long‐term, high‐quality animal models. Moreover, long‐term, well‐controlled, prospective human intervention studies are required to investigate the effect of feasible fish(oil)‐enriched diets on morbidity and mortality of ischaemic ca