We tested semihardened blends of edible oils, suitable for commercial food manufacture, with a lower-than-conventional saturated fatty acid content, for their effects on plasma cholesterol. Twenty-six mildly hypercholesterolemic men took part in a double-blind crossover experiment in which two test blends were compared with two control dietary periods [which resembled the Australian fat intake: proportions of polyunsaturated, monounsaturated, and saturated fatty acids (PMS) 0.4:0.9:1]. PMS in the test diets was approximately 0.8:1.3:1 and resulted in significantly lower LDL-cholesterol concentrations (reductions of less-than-or-equal-to 7.7%). HDL cholesterol and plasma triglyceride were unchanged. The trans fatty acid (mainly elaidic) content of the blends was 16%, raising its contribution to energy by 4% but without apparent effect on LDL and HDL concentrations. Provided the overall ratio of linoleic acid to palmitic acid in commercial edible-oil blends exceeds that in the prevailing national diet, partial hydrogenation will not negate the LDL-lowering potential.