Core shell latex particles with a glassy core and a low T(g) polymeric shell are usually preferred. More so, the glassy core happens to be a fluoropolymer with a shell polymer that helps in processability. We describe here the preparation and characterization of core shell nanoparticles consisting of poly(chlorotrifluoroethylene-co-ethylvinylether) as core encapsulated in poly(styrene-acrylate) copolymer shell using seeded emulsion polymerization method under kinetically controlled monomer starved conditions. Properties of the emulsion using surfactants (fluoro/conventional) and surfactant free conditions were investigated. Average size (100 nm), spherical shape and core-shell morphology of the latex particles was confirmed by dynamic light scattering and transmission electron microscopy. Absence of CAF and CACl peaks in X-ray photoelectron spectroscopy proves that cores are completely covered. Polymerization in the presence of fluorocarbon surfactant was found to give optimum features like narrow size distribution, good shell deposition and no traces of agglomeration. Films of core shell latex particles exhibited improved transparency and enhanced water contact angles thus making them suitable for applications in various fields including coatings. (C) 2011 Wiley Periodicals, Inc. J Appl Polym Sci 122: 1807-1814, 2011