Abstract The influence of grinding in a high planetary ball-mill on the texture and thermal stability of Pb 3O 4 has been studied. The results obtained show that the crystallite size decreases while the level of microstrains increases upon increasing the grinding time. The Pb 3O 4→PbO conversion temperature decreases by increasing the grinding time of the precursor when the orthorhombic phase of PbO (massicot) becomes stabilized with regards to the tetragonal modification (litharge). The analysis of the X-ray diffraction profiles of the lead monoxide obtained from the thermal decomposition of Pb 3O 4 demonstrates that PbO keeps memory of the lattice imperfections of Pb 3O 4. Moreover, higher the grinding time of Pb 3O 4, higher the reactivity of the resulting PbO sample towards reoxidation.