In recent years different international institutions have repeatedly called for states to enter into agreements on the transboundary aquifers they share. Nevertheless, very few agreements have been established. This article examines the few ad hoc legal mechanisms that are in existence, and identifies some possible reasons for states’ reluctance. Finally, this article suggests that there is a need for the international community to stimulate a more cooperative approach to the management of this natural resource based on the preventive and precautionary principles.