Transport infrastructures that connect ports to the hinterland are important enablers of economic growth and development in the region. Therefore, infrastructure owners and governments on different levels are engaging in climate adaptation to adapt transport infrastructures to actual or expected climatic hazards. Existing research on the institutional dimension of climate adaptation had exclusively focussed on trying to understand whether existing institutions allowed and encouraged actors to develop and realize adaptation strategies, and as a result, enhance the adaptive capacity of society. However, the connectivity and interdependencies between institutions that guide actors in their decision-making had not been studied. This research therefore improved and applied the Institutional Network Analysis (INA) method to understand how the various public and private parties interact with each other for climate adaptation of transport infrastructures connected to the Port of Rotterdam.