This study reports on the effects of BaTiO₃—a high dielectric constant additive—addition on charging and filtration properties of meltblown polypropylene (PP) electret filters. Since electrostatic capture efficiency of electret filters is mainly dependent on electrical forces, surface potential and aerosol filtration properties were analyzed and compared. Due to quasi-permanent nature of electret property, stability of charging and filtration performance was also investigated via following an isothermal charge decay procedure. Addition of BaTiO₃ did not alter fiber morphology significantly. Particularly, the stability of electrostatic filtration performance was found to be promising with the addition of BaTiO₃. Possible microstructural changes after addition of BaTiO₃ were investigated via wide angle X-ray diffraction. Changes in crystal structure of PP upon addition of BaTiO₃ did not deteriorate electrostatic properties. Copyright 2015 American Association for Aerosol Research