The ultrafine of Bi 1− x Gd x FeO 3 with x =0, 0.05, 0.1, 0.15 were synthesized by the co-precipitation method. These powders were defined by the X-ray diffraction analysis, transmission electron microscopy (TEM), field emission scanning electron microscopy (FESEM) and vibrating sample magnetometer (VSM). The dielectric constant and dielectric loss were measured by an inductance–capacitance–resistance (LCR) meter. The X-ray diffraction analysis showed that increasing the asymmetry and decreasing the second phases occur by increasing the amount of gadolinium . A phase transformation began from the rhombohedral phase to the orthorhombic one by adding gadolinium in about x =0.15. Gd-doping improved the magnetic properties because the cycloid spins were distorted by adding Gd instead of Bi. Furthermore, the dielectric properties were improved as a result of the reduction in Fe 2+ and oxygen vacancies . The microwave sintering method was used to densify the compact pellets for electrical tests. FESEM images showed that microwave sintering leads to the enhancement of ferroelectric properties due to the high densities of the sintered pellets and the prevention of grain growth. • We synthesized Bi 1− x Gd x FeO 3 with x =0, 0.05, 0.1, 0.15 by co-precipitation. • We highlighted the role of Gd on the magnetic, electric and structural properties. • Gd improved the magnetic and dielectric properties. • Microwave sintering improved the bulk density and other properties.