The present invention relates to a method for preparing an aqueous dispersion of acrylate-siloxane copolymer particles as described herein. The polymer particles comprise structural units of an acrylate monomer; an acid monomer; and a siloxane acrylate monomer of formula I: where R, R1, R2, Y and x are as defined herein. The method provides an efficient way to prepare a high solids content aqueous dispersion of siloxane-acrylate hybrid copolymers with efficient incorporation of siloxane acrylate monomers, low residual monomer, and low generation of unwanted coagulum. The dispersion is useful for forming coatings with improved hydrophobicity, stain resistance, and aesthetic/haptic properties compared with conventional all-acrylic compositions.