Abstract: A process is described for the production of an aqueous polymer dispersion by polymerization of ethylenically unsaturated compounds by means of free-radical initiators in the presence of starch and/or starch derivatives and optional further conventional adjuvants, and which the dispersions are coagulate-free, have a low viscosity, and a small particle size, said process comprising polymerizing an ethylenically unsaturated diene monomer or mixture of monomers consisting of20 to 100% by weight of a diene,0 to 80% by weight of a vinyl-aromatic monomer,0 to 50% by weight of an ethylenically unsaturated monomerin the presence of an aqueous solution or dispersion of dextrins containing 10 parts to 200 parts by weight dextrins, which are optionally chemically modified, wherein the content of said dextrins having a molecular weight in excess of 5000 is at least 50% by weight and the content of dextrins having a molecular weight in excess of 100,000 is not in excess of 5% by weight of the dextrin component.