Compounds in the pseudo-binary BaTiO 3-Ba(Fe 1/2Ta 1/2)O 3 system have been synthesized at 1500°C in air and characterized by X-ray and electron diffraction as well as impedance analysis and Mössbauer spectroscopy. The symmetry of Ba(Fe 1/2Ta 1/2)O 3 is found to be trigonal with the space group P3 m1. Two solid solutions exist in the BaTi 1 -xFe x/1 Ta x/1 O 3 system at room temperature. The first (SS1) is in the composition range 0⩽ x⩽0.07 and is tetragonal, P4 mm, while the second broader solid solution, (SS2) 0.12⩽ x⩽1, is trigonal and has the space group P3 m1. The conductivity becomes higher with reduced amount of Ti in the structure. The activation energy of conductivity differs between the two solid solutions, 0.80 eV for SS1 and 0.30 eV for SS2, which indicates different mechanisms. The maximum of the real part of the permittivity recorded for compounds in SS1 decreases towards room temperature with increasing amount of Fe/Ta doping and a high dielectric constant of around 7000 is found for BaTi 0.94Fe 0.03Ta 0.03O 3.