Twenty-one healthy normocholesterolemic young adults, men and women, completed a randomized 30-d/30-d crossover comparison of the effect of palmolein and olive oil on plasma lipids. The subjects were free-living volunteers who changed to low-fat diets to which one of the test oils was added (used as a spread, for baking, or for frying) in turn. Complete food records were kept throughout: the test oils were compared at 17% of total dietary energy. Under the conditions of this experiment plasma total and low-density-lipoprotein (LDL) cholesterol were almost identical with the two oils, so that when the palmitic acid (16:0) in palm oil replaced oleic acid (18:1) in olive oil the expected increase in LDL cholesterol was not seen. These results indicate that 16:0, though saturated, is not always a plasma cholesterol-raising fatty acid. Palmolein is rich in vitamin E, alpha-tocopherol, and especially tocotrienols, but the latter were barely detectable in plasma.