High performance coatings based on aqueous systems is highly demanded for many industrial applications. One attempt to improve the performance of coatings is the addition of nanoparticles to the main coating polymer. In the present study nanocomposite coatings based on polymethacrylic acid (PMAA) grafted halloysite nanotubes (HNTs) and epoxy functional core/shell polyacrylic latex have been prepared. The modification of HNTs was done via "grafting from" technique including the attachment of a chain transfer agent on the HNTs surface followed by RAFT (reversible addition-fragmentation chain transfer) polymerization of methacrylic acid (MAA). Main acrylic copolymer composed of butyl acrylate/methyl methacrylate soft core and glydicyl methacrylate reactive shell was synthesized via seeded emulsion polymerization. Final crosslinked nanocomposite coatings were prepared by mixing PMAA-modified HNTs (HNTs-PMAA) and acrylic latex in different ratios (2.5 and 5.0 wt.%) followed by drying and curing process. Dynamic mechanical analyses showed that the nanocomposites had significantly increased elastic moduli and tensile strength values as well as enhanced solvent resistance in comparison to the pure acrylic copolymer. The obtained nanocomposite coating system was found to be used in many applications as ductile high performance waterborne functional coatings.