Evidence from epidemiological and randomized controlled trials shows beneficial effects of omega-3 (n-3) fatty acids from fish and plant sources on cardiovascular disease (CVD), especially in patients with preexisting CVD. The optimal dose of n-3 is not yet determined, but prospective secondary prevention studies suggest that the addition of 0.5-1.8 grams/day of marine-derived eicosapentaenoic acid and docosahexaenoic acid, or plant derived alpha-linolenic acid at a dose of 1.5-3 grams/day significantly reduce subsequent cardiac events and mortality. These data have led the American Heart Association Dietary Guidelines committee to recommend to the general population the consumption of at least two servings of fatty fish per week, in addition to vegetable oils high in alpha-linolenic acid. The risk of adverse effects and toxicity from contaminants at this dose is low. The amount of daily n-3 fatty acids recommended for patients with coronary heart disease is 1 gram/day. In patients who cannot consume this dose of n-3 fatty acids through diet alone, addition of n-3 supplements should be considered. Higher doses of contaminant-free n-3 supplements, 2-4 grams/day, can be used in the treatment of hypertriglyceridemia. Data on the content of n-3 fatty acids and contaminants in Israeli bred fish is limited. Thus, caution should be exercised when applying these recommendations to the Israeli fish market.