This paper seeks to contribute to an understanding of the role of power by introducing an organizational perspective to the study of environmental assessment (EA) procedures. By analysing the transboundary environmental assessment (TEA) for the Nord Stream gas pipeline between Russia and Germany, we show that Nord Stream used some of the sentiments imbedded in the institutionalization of TEA and the Espoo convention's formal rules to legitimate its interests. The acts of organizing and organizational relations, however, are what can explain agency and power between organizations and hence the relative power of EA as a governance tool.