A process for preparing polyvinyl-alcohol-stabilized polymers based on vinyl ester, ethylene, and optionally other comonomers, in the form of aqueous polymer dispersions or water-redispersible polymer powders, by means of free radical initiated continuous emulsion polymerization and optionally drying the resultant polymer dispersion, comprising carrying out the emulsion polymerization in minimally two pressurized reactors arranged in series at a temperature of from 40° C. to 100° C. and at a pressure of from 5 to 100 bar, to a residual monomer content less than 3% by weight, and continuing the polymerization in minimally one unpressurized reactor at a temperature of from 20° C. to 60° C. and at a pressure of less than 1.0 bar, wherein the polymerization is initiated using a redox system made from an oxidizing component and a reducing component, at least a portion of the reducing component introduced within the first pressurized reactor.