The authors determined in 3 populations (37 controls, 59 asymptomatic hyperlipemias, and 20 cases of arterial hyperlipemia) the total cholesterol, the HDL cholesterol and the LDL + VLDL cholesterol and their ratio by two methods : precipitation by concanavalin A and ultracentrifugation (AirFuge). These various lipid parameters were compared between 3 populations in order to determine their more or less discriminant character; furthermore, was established the degree of correlation between the results obtained by precipitation with concanavalin A and by ultracentrifugation. The results show : firstly, that the LDL + VLDL was significantly higher and the ratio HDL/LDL + VLDL significantly lower in hyperlipemia and in arterial disease compared with controls ; the HDL was significantly lower in arterial disease than in controls. No lipid parameter permitted one to differentiate between asymptomatic hyperlipemia and arterial disease. Furthermore, the correlation determined by the chi square method was very strong between the results obtained by precipitation with concanavalin A and ultracentrifugation as the coefficient of simple linear regression is very little different from the value + 1. They emphasize the interest of the method of precipitation by concanavalin A which is simple, rapid and very reliable.