Over the last twenty years, the technological improvements of CdTe solar cell have been impressive, and today the performance of these cells is comparable with that of silicon cells. Behind these important results, there have been important research efforts, aimed at exploring every single aspect related to CdTe cell optimization. One of these is reliability, that is fundamental in the perspective of massive commercialization. The aim of this review paper is to explore the main aspects related to the operation and reliability of CdTe solar cells, and describe the most relevant results presented in the literature on these topics. The paper is divided in two parts. The first is dedicated to a general introduction of CdTe issues. In this part, we report the most relevant details on CdTe solar cells from a reliability perspective, including i) a description of the CdTe solar cells development on the years, ii) a description of the main …