Over the last decade, governments of the small Arab emirates in the Gulf region have invested billions of dollars in an attempt to foster rapid growth in their capital cities: the results have been truly dramatic and many of the urban centres in the region have been physically transformed. One interesting aspect of this growth is the fact that rhetoric about sustainability has apparently gained traction in the region, as evidenced by a plethora of urban megaprojects that are all carefully branded as green and sustainable. Urban developments in the Gulf have stimulated a spate of scholarly literature in a number of disciplines, and the debates are ongoing; this article will contribute to the discussion in several ways. It begins with a description of recent economic developments in the Gulf, and goes on to explore and expand the modern phenomenon of ‘instant urbanism’ as it applies to the region. We then compare two notable megaprojects in Doha and one in Abu Dhabi, closely analysing the rhetoric of sustainable urban development that surrounds each. We show the limitations of this rhetoric and uncover the covert aims of these projects, and suggest some of their unintended outcomes