This paper explores the extent to which global environmental justice can serve to serve to interpret negotiations over international transboundary waters. Trade-offs are considered in terms of their spatial and temporal features, while the biophysical traits of water are found to shape the cast and behaviour of actors and institutions suffering injustices, or ignoring or opposing justice claims. Applications of the frame to recent negotiations along the Nile and Jordan rivers show that inequitable outcomes can be entrenched by apparently fair processes. The negotiations procedures do not recognize the power asymmetry that exists between the actors, and thus fail on Rawls' precondition of equality for justice, suggesting that while distribution may be a necessary condition for justice, process alone is not necessarily so. The analysis also finds that focus on the international can obscure injustices at the sub-national level, and that environmental issues must be considered within the social justice context they derive from. One practical implication is that evaluations of negotiations over international transboundary waters should consider their outcome first, followed by investigation of the asymmetry in power that undermines the processes.