Abstract: The invention relates to a process for microencapsulation of phase change materials based on free radicals polymerization comprising: a) the preparation of i) a solution with, at least, a hydrophilic liquid and a stabilizer (continuous phase) and ii) a solution with, at least, a phase change material, a free radical initiator and a polymerizable material (discontinuous phase); b) the preparation of an emulsion by dispersing the discontinuous phase in the continuous phase under vigorous stirring; and c) the polymerization of monomers until the phase change material becomes microencapsulated. This process is simple and effective and avoids the use of hazardous compounds. The invention also relates to microcapsules obtainable by said process and to the use thereof in the thermal protection and storage of heat.