A high intake of fat, and in particular saturated fat, is associated with an increased risk of coronary heart disease. Reduced intake of spreads had therefore generally been recommended. A special type of "heart-friendly" margarine, a plant sterol enriched margarine, has been a commercial success since it was introduced in 1995. Such margarine may be defined as a functional food, and is not available in Norway. The aim of this article is to give an overview of plant sterols and their distribution in different foods as well as of their hypocholesterolaemic effects.The Medline database was used to identify relevant literature.An intake of 2-3 grams of plant sterols/day is associated with a 10% reduction of total cholesterol and a 13-15% reduction of LDL cholesterol, whereas HDL cholesterol remains largely unchanged. This amount of plant sterols may be incorporated into approximately 20 grams of margarine. Subjects that are poor responders to treatment with statins may benefit from such margarine, and also children with familial hypercholesterolaemia. Such margarine may have a potential in addition to dietary treatment, as an additional hypocholesterolaemic effect is observed in subjects who already have a healthy diet.A daily intake of approximately 20 grams of plant sterol enriched margarine is associated with significant reductions of both total and LDL cholesterol. However, use of plant sterol enriched margarine can not replace the overall beneficial effects of a well balanced heart-friendly diet.