This work presents an analysis of the microstructural evolution of solid solutionsSolid solutions type Ba1-xHoxTi1-x/4O3 with x = 0.0, 0.003 and 0.005 Ho3+Ho3+ (wt. %) sintered at high temperaturesTemperature in air. The samples were prepared from stoichiometric mixtures of BaCO3, TiO2, and Ho2O3, which were previously ground for 6 h in a polypropylene mill using zirconia balls and acetone as a control medium. The crystalline phases developed during sinteringSintering were identified by X-ray diffraction (XRDX-Ray Diffraction (XRD)), the determination of lattice parameters, crystallite size, and phase composition was performed by Rietveld analysis. The results obtained confirmed the presence of the ferroelectric tetragonal BaTiO3BaTiO3 phase doped with Ho3+Ho3+ for the samples with x = 0.003 and 0.005 Ho3+Ho3+ (wt. %). The results obtained by HRSEM-EDS indicated the incorporation of Holmium in the crystalline structure of BaTiO3BaTiO3 and its influence as a dopant on the grain sizeGrain size.