This article examines the institutional, political and regulatory dimensions of environmental assessment (EA) processes. While EA is most often conceptualized as a regulatory instrument, this article contends that viewing EA in this narrow fashion obscures the broader implications and significance of EA as a distinct form of governance. When conceived as a mode of governance, EA varies considerably in terms of the key governance characteristics emphasized in this symposium. The empirical evidence rests upon three cases studies looking at very different multi-level governance contexts: the Tamar Valley Pulp Mill in Australia, the Whites Point Quarry in Canada, and the Byströe Canal Project in the Ukraine. The case study analysis identifies large variations in the institutional, political and regulatory form that EAs take, indicating that approaches identifying EA as a form of ‘New Governance’ are overly simplistic. The analysis also points to the multi-directional influence of different governance dimensions. The insights derived from the use of the three dimensional framework validate its value as an analytical tool.