This paper studies environmental norm contestation in Cambodia's hydropower sector, exemplified by the Kamchay Dam. In Cambodia we can observe different discourses in relation to hydropower. These stem directly from a local contest over the path of Cambodia's development, but use global norms as reference points: one emphasizes environmental protection, using environmental impact assessment (EIA) as point of reference; and one emphasizes the utility of the clean development mechanism (CDM) to attract large-scale investment into the energy sector while downplaying the need for environmental protection. While EIA and CDM are complementary, key actors present them as contradictory. This produces a normative fragmentation of the field of environmental protection. The paper argues that the norm diffusion literature, by presenting norm conflicts as hierarchical local–global conflicts, has paid insufficient attention to the fact that local actors actively draw on global norms to justify domestic development policies. More emphasis on this phenomenon will lead to a better understanding of the role of global norms in domestic politics and will enhance our knowledge of how domestic development policies are contested.