In the past decade, the economic situation started to change due to the raise in energy prices, hence researchers began to give more attention to phase change materials (PCM) applications for heating and cooling of buildings. PCM can be used for temperature regulation and their high storage capacity can reduce energy consumption in buildings. The development and testing are usually conducted for prototypes of PCM wallboard and PCM concrete systems to enhance their thermal energy storage capacity, with main concern in peak load shifting and solar energy utilization. However, for a more adequate integration, the industry needs to optimize the performance of PCM. In this work we present a review on the thermal energy storage with phase change materials (PCM) in buildings, and focus on the evaluation of its applications in the Mediterranean region. The efficacy here is related to the availability of PCM with suitable fusion temperatures for the studied climate and the period by which the savings in energy will compensate the relatively high prices of PCM. The studies undergone in Cyprus and other Mediterranean countries are promising and show the importance of using PCM in improving building energy performance and maintaining low heating and cooling loads. Furthermore, the increasing number of studies on PCM in many Mediterranean countries should therefore set the subject seriously into discussion in other neighboring countries like Lebanon, where energy saving is vital due to the increasing price of fuel. On the other hand, we highlight on the importance of the characterization of the thermo-physical properties of PCM through efficient experimental and numerical methods for their adequate integration in building applications. This study thus presents a short overview of basic material characteristics and necessary energy performance data based on available experiences to evaluate the efficacy of future applications of PCM in Mediterranean countries.