The present invention relates to a process for preparing aqueous, hydroxy-functional polyester-polyacrylate dispersions having a cosolvent content of 0 to 5% by weight, based on the weight of the dispersion, by preparing a polymer P) in a first step by polymerizing A) a mixture of vinyl monomers that are capable of free-radical copolymerization, in the presence of B) one or more compound(s) of formula (I) wherein R1 is an aliphatic, araliphatic or aromatic radical having 1 to 18 carbon atoms, R2 is H or CH3, R3 and R4 are identical or different aliphatic radicals having 1 to 7 carbon atoms, and n is 1 to 4, and then mixing polymer P) in a second step with C) one or more polyester polyols having a hydroxyl number of 10 to 500 mg KOH/g solids and an acid number of >0.5 to ≦30 mg KOH/g solids, and dispersing the resulting polymer mixture in water in a further step, before or after addition of a neutralizing agent. The present invention also relates to the aqueous polyester-polyacrylate polymer dispersions obtained in accordance with the process of the invention and to aqueous coating compositions containing the aqueous polyester-polyacrylate polymer dispersions of the invention.