The phase diagrams for the SDS/PPG (MW = 425 and 1000)/H2O ternary systems have been studied. The systems show an L phase and two liquid crystalline regions characterized as hexagonal and lamellar, respectively. The low viscous L phase, which is clear and isotropic, extends from the water-rich corner to the polymer-rich corner in both phase diagrams and is similar to the L phase in the CTAB/PPG (MW = 425 and 1000)/H2O systems. Conductivity, steady-state quenching fluorescence, and rheology have been used to study the physical properties of the L phase; its influence on the basic hydrolysis of the crystal violet has been analyzed in order to elucidate the presence of a reverse micelles region at high PPG concentration.