The hypocholesterolemic effect of a vegetable dietary protein was studied by comparing egg white protein and faba-bean protein concentrate in 4 hyperchol-esterolemic persons (3 type IIA, 1 type IIB) and 1 normal individual. To maintain stable body weight, participants were kept for 1 month on an isocaloric diet (20% protein, 48% CHO, 32% fat, P/S=2) and then hospitalized for two consecutive cross-over periods of 18 days each, when they again received an isocaloric diet but of different composition (15% protein, 59% CHO, 26% fat, P/S=2), with the two protein sources as the basis of the cross-over. Serum total, LDL-, VLDL- and HDL-cholesterol and total and VLDL-triglycerides were analyzed every three days. Compared to baseline values, serum total and LDL-cholesterol decreased during both diets, reaching statistical significance for the egg white diet; serum HDL-cholesterol significantly decreased on the faba-bean diet; serum total and VLDL-Tg did not show any significant changes. Comparisons of lipid values at the end of each diet (faba-bean vs. egg white) showed small differences in mean values, none statistically significant. In conclusion, evidence was not obtained that the faba-bean diet produced a significant lowering of serum total and LDL-cholesterol.