Flexible BaTiO3 films as dielectric materials for high energy density capacitors were deposited on polyethyleneterephthalate (PET) substrates by r.f. magnetron sputtering. The growth behavior, microstructure and electrical properties of theflexible BaTiO3 films were dependent on the sputtering pressure during sputtering. The RMS roughness and crystallite size ofthe BaTiO3 increased with increasing sputtering pressure. All BaTiO3 films had an amorphous structure, regardless of thesputtering pressures, due to the low PET substrate temperature. The composition of films showed an atomic ratio (Ba:Ti:O)of 0.9:1.1:3. The electrical properties of the BaTiO3 films were affected by the microstructure and roughness. The BaTiO3 filmsprepared at 100mTorr exhibited a dielectric constant of ~80 at 1kHz and a leakage current of 10−8A at 400kV/cm. Also, filmsshowed polarization of 8µC/cm2 at 100kV/cm and remnant polarization (Pr) of 2µC/cm2. This suggests that sputter depositedflexible BaTiO3 films are a promising dielectric that can be used in high energy density capacitors owing to their high dielectricconstant, low leakage current and stable preparation by sputtering.