This article explores major findings and evolutions in understandings of transboundary water conflict and cooperation over the last three decades, focusing on the trends emerging from the Transboundary Freshwater Diplomacy Database. It is found that since the 1940s, countries tend to cooperate over shared water resources, in contrast to media portrayals of ‘water wars’. Water conflicts, which have increased slightly since 2000, are mostly fuelled by water quantity disputes or unilateral infrastructure developments. Institutions play a role in facilitating cooperation and reducing conflict over shared waters, but their growth and adoption have slowed over the last few decades.