The preparation of poly(hexylacrylate)(core)-poly(ethyleneglycol methacrylate)(shell) (PHA-co-PEGMA) nanogels, to be used as fillers in nanocomposite hydrogels, is reported. Stable nanogels with particle sizes between 90-300 nm were obtained varying the conditions of synthesis. The synthesis recipe of the nanogels could be easily scaled up. Purified and dispersed nanogels in aqueous solution were used as soft fillers for poly(2-hydroxyethyl methacrylate) (PHEMA) hydrogels, crosslinked with ethylene glycol dimethacrylate (EGDMA). The obtained nanocomposite hydrogels exhibit a larger swelling capacity and a higher thermal stability in comparison with the non-filled PHEMA hydrogels. Young, storage, and lost moduli, increase largely, in the better case up to 72.5% in the swollen state; while in the dry state the storage modulus increase up to 4.7 fold with a very low load on nanogels (0.64 wt%); resulting in biomaterials with improved properties with potential applications in medical devices. POLYM. ENG. SCI., 59:170-181, 2019. (c) 2018 Society of Plastics Engineers