Process for preparing an aqueous dispersion of hydrophilic polymers, according to which, in a reactor: a reaction medium is prepared in the form of an aqueous solution comprising water-soluble monomers, one or more salts and/or one or more dispersant organic polymers; the monomers are polymerized; the polymer obtained is discharged from the reactor; wherein the pressure of the reaction medium is lowered to a value below 200 mbar.