Surface migration of unmodified inorganic or polymer core‐inorganic shell nanoparticles has limited their application for improvement of pressure‐sensitive adhesives (PSAs) properties. The efficiency of utilization of modified inorganic nanoparticles with sticky polymer brushes was investigated to overcome this problem. For this purpose, polymethacryloxypropylsilsesquioxane‐acrylic core‐shell (CS) nanoparticles were synthesized and added to poly(methyl methacrylate‐co‐butyl acrylate) (MBC) acrylic PSA through latex blending. Using CS nanoparticles, a concomitant increase in the peel and shear strengths of the acrylic PSA was achieved, and also the limitation of surface migration of nanoparticles at high volume fractions was overcome. Moreover, CS nanoparticles acted as a compatibilizer for MBC chains, rich in methyl methacrylate (MMA) or butyl acrylate (BA). These MMA‐rich and BA‐rich chains were formed during the synthesis of MBC latex through batch emulsion copolymerization method, due to the difference in the reactivity ratio of BA and MMA radicals. The compatibility of CS nanoparticles with each of the components of MBC was systematically investigated in terms of grafting density, swelling ratio, and thermodynamic affinity and was correlated to the final properties.