The authors of this paper propose a collaborative approach towards an integrated vulnerability assessment to climate change in Germany that attempts to bridge the gap between scientific output and policy demand. The approach is the first really integrative vulnerability assessment for the whole Germany as it considers not only 16 sectors, but also interconnections between these sectors and cumulative effects in three time slices (presence, near and remote future). Furthermore, the approach takes into account both changes in the climatic conditions and socio-economic development trends. Conceptually the approach follows the definition of vulnerability as used by the IPCC, but it has modified this basic concept. The paper concentrates on the selected methodological framework, the collaborative research design and those preliminary results of the nationwide vulnerability assessment that are transferable to other settings. This vulnerability analysis forms part of the German Adaptation Strategy (DAS). It is based on transdisciplinary collaboration and joint development of methods within the Vulnerability Network, a consortium of 16 federal agencies and institutions in Germany, alongside a research team lead by adelphi.