Thin and thick BaTiO3-polymer nanocomposite dielectric films were prepared using BaTiO3 nanoparticles and poly (methyl methacrylate) (PMMA). The cubic BaTiO3 (~ 30-60 nm) and tetragonal BaTiO3 (~ 120 nm) synthesized via hydrothermal/solvothermal route were used as nanofillers. The dielectric constant of 9 was achieved for the films of thicknesses in the 150-300 nm range, which corresponds to a capacitance density of 32 nF/cm2. The dissipation factor of the composite film was of a value of 0.04 at 10 kHz. Thick films (~ 16.3 µm) were prepared by doctor blade method and tested for their capacitance and dielectric properties in the 10-100 kHz frequency range for cubic and tetragonal BaTiO3. The BaTiO3 particles were dispersed homogeneously in the films at lower filler loading. The homogenous distribution of BaTiO3 achieved by surface functionalization of BaTiO3 nanoparticles and use of tetragonal BaTiO3 resulted in the improvement of electric properties of thick and thin films.