This paper presents the results of preparing and investigating the solid solution of lead barium zirconate titanate stannate (Pb1−xBax)[(Zr1−yTiy)1−zSnz]O3 with x = 0.25, y = 0.35 and z = 0.00, 0.02, 0.04, 0.08, 0.10. Ceramic samples were obtained from oxides and carbonates using conventional ceramic technology and pressureless sintering. The results of Energy-dispersive X-ray spectroscopy (EDS) investigations, XRD studies, as well as dielectric measurements and electromechanical investigations are presented. It was stated that at the room temperature, the structure of the investigated samples is pseudo-cubic, typical for relaxors. Maximal value of elementary cell parameter is observed for z = 0.02, and for higher values of z, we observe almost linear decrease with increasing z. It was found that with increasing content of the Sn, the temperature Tm at which dielectric permittivity reaches its maximum decreases. Analyzing P-E hysteresis loops it was stated that the phase transition in the investigated samples takes place at temperatures approximately 100°C lower than the temperature of the dielectric permittivity maximum. The temperature of phase transition was calculated also from hysteresis loops and compared with that obtained from measurements of dielectric permittivity.