The liquidus surface of the Ag + Au + Pb system has been determined by differential thermal analysis. In the temperature range 973-298 K, experiments were performed along the four following sections : x(Au)/x(Pb) = 1/3 with 0 < x(Ag) < 0.50; X(Au)/x(Ag) = 1/4 and 1/1 with 0.30 < x(Pb) < 1; and x(Pb) = 0.4 with 0 < x(Ag) < 0.54. These results allow the liquidus surface and the ternary eutectic valley to be proposed.