This paper reviews the current state of research on Water Users' Associations in canal irrigation. It argues that, while it makes several important contributions to our understanding of water institutions, collective action and local governance, it suffers from several weaknesses. Technology is treated as a black box. There is a very static and instrumental perspective. There is also a bracketing of the social relationships of which collective action is an expression. This paper concludes that further research is needed in order to understand the organizational dynamics of water users¿ associations and how different technological conditions of water distribution influence the possibilities for collective action. Research is also needed on the interplay of the broader contextual factors under which water users¿ associations operate and on the effects of WUA formation on social power relationships, water management and distribution practices.