Further work on the micellar properties of ethoxylated anionic and cationic surfactants is reported. Micellar molecular weights in water obtained from light scattering and corrected for charge effects, increased with increase in hydrocarbon chain length but decreased with increase in ethoxy group number. Micellar size of the ethoxylated surfactants was smaller than usual for paraffin chain salts. Micellar weights decreased 18% as the temperature increased from 25 to 45 °C. Addition of 0.1M. electrolyte increased micellar weight four fold. Analysis of the hydrodynamic data showed the ethoxylated micelles were hydrated with two molecules of water per ethoxy group. The hydrocarbon chain had little effect on hydration.