This article contends that notions of «peace» and «justice» in cross-border water management vary in different world regions. Moreover, it argues that «peace» and «justice» can be explained by analyzing the interaction between «regional» interpretations and implementation of water security norms and local cross-border power structures. «Regional water security» is defined as the normative commitment to provide necessary water resources to communities within world regions. «Power,» which is defined traditionally as «the ability of actors to obtain their objectives despite opposition» is viewed as a function of political entrepreneurialism and opportunity structures. This article derives from a review of the pertinent literatures on «water security» and «water justice,» the two elements of «water peace» as well as scholarship on cross-border water management in different world regions. It discusses water governance within the framework of cross-border politics and comparative regional integration. It also includes analysis of the policy documents and websites of seventeen regional organizations as well as interviews with key actors and local experts on water management in specific cross-border case studies. The article is divided into five sections. Following this introduction, part two examines «water security» and «water justice» in international affairs. Part III then discusses «power» in cross-border water governance debates and addresses the transnational face of water security discussions. Part IV presents a comparative examination of cross-border «water justice» in selected world regions which is followed by theoretical considerations that are addressed in part V, the conclusion. In general, the article emphasizes the need to promote comparative cross-regional research on cross-border water governance in order to examine how «peace,» «security» and «justice» are framed in debates over water resources.