As a part of studies related to the effects of dietary fats with different fatty acid configuration of the glycerides on the concentration and composition of plasma and liver cholesterol, weanling male rats were fed on the diet containing linoleic acid either as a free form or trilinoleate for 8 and 13 weeks. When the rats were kept on the diets that contained essential fatty acids (EFA) at the level of the minimum dietary requirement, no differences were found in the concentration and composition of plasma and liver cholesterol between two types of EFA. Administration of cholesterol (1%) also gave similar results. The data indicate that which types of linoleic acid have similar effect on the plasma cholesterol level.