In this study, a poly(methyl methacrylate) (PMMA) shell 1-tetradecanol core microencapsulated phase change material (MPCM) was produced using the Pickering emulsion technique. Characterization tests of the produced MPCMs were performed using Fourier transform infrared (FT-IR) spectroscopy, particle size distribution (PSD) analysis, differential scanning calorimetry (DSC), scanning electron microscopy (SEM) and thermogravimetric analysis (TGA) techniques. The latent heat, melting temperature and encapsulation rate of MPCM were determined and they were found as 108.4 J/g, 33 °C, and 46.7 % for heating period, respectively. The effect of 1-tetradecanol@PMMA MPCM on the physical, mechanical, and thermal performance properties of cementitious mortars was also investigated in the study. For this reasons 1-tetradecanol@PMMA MPCMs are included in mortar mixes at 5 %, 7.5 %, and 10 % by weight of cement. As the MPCM ratio increased, the water absorption rate and porosity increased, while the workability, unit weight of the mortar, ultrasonic pulse velocity, flexural strength and compressive strength parameters decreased. The compressive strength of the mortar containing 10 % MPCM on the 28th day was measured as 34.74 MPa. The highest thermal storage capacity was found in mortars containing 10 % MPCM. When the thermal performance of the reference and 10 % MPCM-containing mortars were compared, the indoor temperature differences at the end of the heating and cooling periods were measured as 4.7 °C and 3.9 °C, respectively. The results showed that MPCM produced by the Pickering emulsion technique has the potential to increase thermal comfort in buildings, reduce fuel consumption used for heating purposes and, accordingly, reduce carbon emissions.