The aim of the present work was to develop the crosslinked polymeric nanocapsules for drug delivery from the SiO2 nano-templates via surface-initiated atom transfer radical polymerization (SI-ATRP) technique. The crosslinked polymeric nanocapsules were fabricated via the SI-ATRP of 2-hydroxyethyl acrylate (HEA) from initiator modified silica nano-templates. After the hydroxyl side-groups of the polymer grafted silica nanoparticles (SN@PHEA) were crosslinked with hexamethylene diisocyanate (HDI), the silica templates encapsulated in the crosslinked polymer shells were removed by being etched with HF to produce the crosslinked polymeric nanocapsules. The diameter of the polymeric nanocapsules is in the range of 20–40 nm, characterized by transmission electron microscopy (TEM).