Since 2008, the International Climate Initiative of the Federal Ministry for the Environment, Nature Conservation and Nuclear Safety has been financing climate and biodiversity projects in developing and emerging as well as in transition countries. This strategic evaluation of the catalytic impact of such projects in the area of ecosystem-based adaptation to climate change contributes to the three objectives of the evaluation system of the International Climate Initiative: Learning, accountability and steering. The evaluation analyzes “whether and how International Climate Initiative-funded projects on ecosystem-based adaptation play a catalytic role either at the national level of the partner countries and/or at the international level.” It provides insights into the underlying causal mechanisms, identifies their relative importance, and provides evidence-based lessons learned and recommendations for how the Ministry’s funding practice can be made even more impactful. This theory-based mixed methods evaluation employs various synthesis techniques, process tracing, portfolio analysis and Qualitative Comparative Analysis for contribution analysis and understanding the strength of evidence. The evidence base consists of project reports from 33 International Climate Initiative ecosystem-based adaptation projects, all of which started between 2008 and 2017. They were complemented by interviews, three country case studies (Vietnam, Peru and Grenada), and an in-depth study of a global platform project.