The present invention relates to a process for preparing aqueous binders for aqueous coating compositions by reacting a mixture of A) 9.9 to 85 wt. % of a hydroxy- and acid-functional poly(meth)acrylate andB) 14.9 to 90 wt. % of a hydroxy-functional, fatty acid-modified polyester with C) 0.1 to 20 wt. % of a diisocyanate having a molecular weight of 140 to 318, to form urethane groups and then dissolving or dispersing the reaction product in water with prior or simultaneous neutralization of at least a portion of the carboxyl groups present, wherein the sum of the percentages of A) to C) add up to 100. The present invention also relates to the aqueous binders obtained by this process and their use, optionally combined with other oxidatively drying lacquer resins, in air- and/or heat-drying, two-component coating compositions, preferably aqueous polyurethane coating compositions, or in combination with optionally blocked polyisocyanates and/or amino cross-linking agents in aqueous heat-curing coating compositions.