This paper presents the effect on the structural characteristics and magnetic properties of replacement of cations occupying sites A and B, in the crystal structure of BiFeO3 (BFO) in their structural and magnetic properties. The citrate gel method was used to synthesize powders of the systems Bi1-xLaxFeO3 with (x = 0.10, 0.15, 0.20), BiFe1-yCoyO3 (y = 0.03, 0.06, 0.09) and Bi1-xLaxFe1-yCoyO3 with x = 0.10, 0.15, 0.20 and y = 0.03). The obtained powders were subjected to a leaching process to minimize unwanted phases. It was observed, using structural characterization by X-ray diffraction, and morphological characterization by scanning electron microscopy, that cationic substitution alters the crystal structure and the particle size of BFO. Addition of lanthanum and cobalt generates ferromagnetic behaviour reflected in magnetic hysteresis curves obtained at room temperature.