Polycrystalline samples of BaTiO3 doped with 2.0 at.% Mn were prepared by solid-state reactionat various temperatures (Tan) ranging from 500 to 1350 C, used high-pure powders of BaCO3,TiO2, and MnCO3 as precursors. Experimental results obtained from x-ray diffraction patterns andRaman scattering spectra reveal that tetragonal Mn-doped BaTiO3 starts constituting as Tan 500 C. The Tan increase leads to the development of this phase. Interestingly, there is thetetragonal-hexagonal transformation in the crystal structure of BaTiO3 as Tan  1100 C. Suchthe variations influence directly magnetic properties of the samples. Besides paramagneticcontributions of Mn2þ centers traced to electron spin resonance, the room-temperatureferromagnetism found in the samples is assigned to exchange interactions taking place betweenMn3þ and Mn4þ ions located in tetragonal BaTiO3 crystals.