Investigations of crystal structure and magnetic properties of Bi0.8(Gd1−xBax)0.2FeO3 (x = 0, 0.5, 1) samples have been performed. The Bi0.8Gd0.2FeO3 and Bi0.8Ba0.2FeO3 compounds have been shown to crystallize in the polar space groups Pn21a and R3c, respectively. It has been found that no continuous series of solid solutions is formed in the Bi0.8(Gd1−xBax)0.2FeO3 system: the crystal structure of the Bi0.8Gd0.1Ba0.1FeO3 sample is characterized by a coexistence of Pnma and R3c structural phases which differ in their chemical compositions. All of the Bi0.8(Gd1−xBax)0.2FeO3 (x = 0, 0.5, 1) compounds have been found to possess a spontaneous magnetization at room temperature. For Gd-containing samples, a significant enhancement of the magnetization takes place with decreasing temperature.