The evaluation case study of the Climate Technology Centre and Network (CTCN) was on one hand requested by the European Commission, one the of the co-financiers of the CTCN. On the other hand, it is part of a larger evaluation effort by the UNEP Evaluation Office of two umbrella projects (12/3-P1 and 12/3-P2) of the UNEP´ Division of Technology, Industry and Economics (DTIE) Energy Branch. The purpose of the assessment of the CTCN is to measure results to date (accountability), and to generate lessons and recommendations to improve the performance of the Centre and Network (learning). The case study is limited by the short time in which it has to be completed and by the limited availability of stakeholders during their preparations for the Paris COP in December 2015. Therefore, the evaluation focuses on some key questions that contribute to the UNEP Evaluation Office’s evaluation of the umbrella programmes. The case study was carried out from September to February 2016 with a draft report submitted by November 2015. Further evaluations are planned in the context of a joint evaluation of UNIDO/UNEP as well as by the UNFCCC. While these evaluations will benefit from the further progress in the implementation of the CTCN, and thus be able to answer more in-depth questions with respect to effectiveness, impact and sustainability of the CTCN, the current case study is also providing insights and open questions for these evaluations.