The goal of this paper is to analyze the complex institutional landscape of adaptation finance in Vietnam, a middle-income country highly vulnerable to the impact of climate change. While resources from international organizations and national authorities occupy a prominent position in adaptation funding, the use of local resources that directly or indirectly support adaptation practices is also an important factor to consider. We hypothesize that it is that interplay between official climate change finance on the one hand and local social dynamics on the other hand that shapes the structure of adaptation funding. These very particular financing circuits consequently determine the kind of adaptation actions that are actually implemented. The paper unfolds the adaptation finance flows at all scales by using qualitative field studies, technical and legal reports, and a wide-ranging literature on adaptation project financing, and thus identifies three types of dialectical tensions that might hinder Vietnamese institutional readiness for adaptation finance: the adaptation/development financing nexus, the adaptation/reaction financing behaviors, and the endogenous/exogenous financing dichotomy. Ultimately, the paper derives from these dialectical tensions within the architecture and functioning of adaptation finance key takeaway messages for a prospective analysis of adaptation funding that better informs adaptation finance policies.