The paper shows the possible obtaining of the solid solution of LaNiO3 and LaFeO3 by a sol-gel like method with propionate acid as solvent. In order to understand the role of the precursor nature in function of the starting materials on the formation or not of LaNixFe1-xO3, an identification using infrared spectroscopy was made. The solid solution formation needs the limitation of the preferential LaFeO3 in order to permit the introduction of nickel into the structure. Nitrate salts of iron and lantanum gave pure LaNixFe1-xO3 perovskite with a high homogeneity even at nanoscopic scale.