The present work focuses on the reaction to fire of a cement mortar containing phase change material (PCM), which is embedded in a lightweight aggregate, for buildings. Several samples containing different PCM mass fractions have been prepared and tested in order to study the influence of the quantity of PCM on fire behaviour. The enthalpy-temperature of the PCM curve has been measured using the T-history method, and the effect of the PCM on the thermal behaviour of the cement mortar material has been studied using an experimental setup. With the aim of characterizing the reaction of the composite material to fire, various small scale laboratory tests have been carried out, paying special attention to the production of burning drops during combustion, smoke release and flame persistence. (C) 2014 Elsevier B.V. All rights reserved.