Dielectric and ferroelectric properties were studied in Sr0.85−yPr0.15VyBi2Ti2O9 polycrystalline samples where cation vacancies were induced. DRX characterization shows that the Aurivillius structure can accept 10% of induced vacancies without precipitation of second phases. Thermoelectric analysis and ferroelectric hysteresis measurements show that the vacancies modify the transition temperature Tc and slightly the polarization values. From the ε-T curves it was observed that the polarization magnitude and Tc are affected as a consequence of the induced vacancies. A broad peak at Tc, typical of the diffuse phase transition behavior of this material was also observed. Furthermore, the induced vacancies in praseodymium-modified SBT produce an increased on Tc from ∼180 to ∼240 °C, these facts show that induced vacancies in the structure are a tuning mechanism for the dielectric and ferroelectric properties.