Water diplomacy will play an increasingly important role in preventing, mitigating and resolving a growing number of water-related conflicts around the world. However, the theory and practice of cooperation over shared waters and the implementation of multi-track water diplomacy are not sufficiently developed. Concepts and approaches such as multi-level water governance, adaptive water governance, the mutual-gains approach and instruments for benefit sharing need to be further developed and operationalized. The objective of this publication is to specify a conceptual and analytical water diplomacy framework that identifies the key factors that affect water cooperation. Knowledge of the key determinants of cooperation not only contributes to the existing body of academic knowledge, but can also help to bolster cooperation over shared waters.