Phase diagrams of aqueous two-phase systems composed of a triblock copolymer (L35) 1900 g.mol(-1), sodium tartarate, sodium citrate, or sodium nitrate were determined at (283.15, 298.15, and 313.15) K. The temperature effect on the position of the binodal curves was not relevant, indicating a small enthalpic contribution associating to the phase segregation. The ability of three salts to induce the formation of the biphasic system with L35 followed the order sodium citrate > sodium tartarate > sodium nitrate. The preference of a salt-inducing phase segregation follows the Hofmeister series.