The paper begins by reviewing literature suggesting that sports stadia have negligible or even negative economic impacts upon their host city or region. This paper suggests that in some specific cases the picture may not be so clear cut. It examines the operations of the Wales Millennium Stadium since its inception in 1999 and suggests that the stadium has had a positive impact upon economic demand and hence employment and value added in Cardiff. Moreover, the research suggests that much of this increased demand originates from visitors resident outside Cardiff and Wales, and hence the stadium functions as a notable ‘exporter’ for the city, and is moreover critical to its tourism performance. Conversely, the paper finds that stadium effects are limited in scale compared to city and regional economic activity in aggregate and concludes that the stadium's relative economic importance is driven by its atypical operation compared to other stadia.