Global water quality is degrading, contributing to water stress and placing pressure on dynamics between riparian states in transboundary basins. In spite of this trend, limited research has assessed the relationship between inter-state conflict, cooperation, and water quality, constraining knowledge for effective interventions and identification of potential conflict risk. To address this gap, a literature review was conducted on the state and drivers of transboundary water quality-related interactions. Finding that interactions have not been analysed recently and that many underlying drivers are proposed but not thoroughly evaluated, the review identifies opportunities for future research to strengthen transboundary water quality governance.